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REESE  LIBRARY 


UNIVERSITY  OF  CALIFORNIA. 


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' 


PRACTICAL 
MINING  AND  ASSAYING 


BY 


FREDERIC    MILTON  JOHNSON 


PRICK 
ONE    DOLLAR 


SAN    FRANCISCO 

PUBLISHED   BY   THE    AUTHOR 

1897 


O 


COPYRIGHTED,    1897 

by  F.  M.  Johnson. 
Certificate   No.  32408 C2 


PREFACE. 

This  work  is  the  result  of  fifteen  years  of  prac- 
tical experience  in  the  mountains,  the  mines,  the 
mills  and  the  assay  office,  and  is  published  for 
the  benefit  of  the  prospector,  the  miner  and 
those  who  may  desire  to  obtain  a  general  knowl- 
edge of  practical  mining  and  assaying. 

I  have  endeavored  to  make  it  as  brief  and 
plain  as  possible  for  those  who  have  not  had  the 
opportunity  to  acquire  the  desired  information 
on  this  subject,  and  this  alone  has  prompted  the 
publication  of  this  pocket  edition  of  PRACTICAL 
MINING  AND  ASSAYING. 

FREDERIC  MILTON  JOHNSON. 


ERRATA 

PAGE   29: —    Fourth  line,   use  Sulphuric  acid 
instead  of  Muriatic  acid. 

PAGE  50:—  Third  line,  after  the  word  "with" 
add  the  word  "water". 


CONTENTS. 

Assaying page  33 

Assay  for  Pure  Concentrates 49 

Amalgamation •.  55 

Bead  Scale 39 

Chlorination : 59 

Cupellation 38 

Concentrator 53 

Chemical  Assay  for  Gold 27 

Dressings  for  Different  Ores 44 

Dressing  the  Plates 56 

Formation 11 

Fluxes 41 

Glossary  99 

How  to  Keep  Mercury 56 

Introduction 7 

Leveling  Instrument 65 

Measuring  Inaccessible  Distance 62 

Measuring  Inaccessible  Distance,      (with   in- 
strument)   67 

Metals  that  are  Dissolved  in  Acids   49 

Milling  Test  for  Free  Gold 26 

Mining  Laws 90 

Ores  (see  rocks) 

Panning  for  Gold 32 

Parting ' 38 

Preface 3 

Pulp  Scale 35 

Rocks 12 

Sundry  Items 68 


6  PRACTICAL   MINING 

Tables,    Assay  Table,  (240  grains) 73 

Assay  Table,  (20  grammes)    76 

Cast  Iron  Pipe 83 

Natural  Sines 84 

Pelton  Water  Wheel 89 

Relative  Value  of  Weights 81 

Specific  Gravity,   Weight  and  Melt- 
ing Point 80 

Wrought  Iron  Pipe 82 

Test  for  Arsenic 31 

Black  Zinc  Blende 20 

Fluorspar 30 

Gold 26 

Gold    (with  gunpowder) 28 

Iron   26 

Gypsum  (heavy  spar) 31 

Lime  and  the  Carbonates 30 

Lime,  Magnesia  and  Barita 31 

Manganese 29 

Mercury  (cinnabar) 30 

Nickel 25 

Nitrates  (chilly  nitre,  etc.) 32 

Red  Copper 29 

Silver .  24 

Tellurium   31 

Zinc 29 

Testing  Ores  with  Acids 50 

Veins  or  Lodes 21 

Weighing .40 

Wet  Assay 25 


INTRODUCTION. 

Carbon  is  the  base  of  the  vegetable  and  organ- 
ized world,  and  quartz  or  silica  is  the  chief  or 
principal  of  the  mineral  world.  A  particle  of 
any  one  substance  is  a  unit  or  simple.  There  are 
64  simple  substances  known.  Those  that  are  un- 
known are  termed  elements,  which  have  a  tend- 
ency to  combine  with  know  substances  or  other 
elements,  forming  compounds  with  the  different 
substances  under  various  conditions  of  tempera- 
ture, pressure,  electricity,  etc.  All  may  assume 
either  a  liquid,  solid  or  gaseous  state.  These 
elements  may  be  mixed  in  any  proportion,  but 
they  combine  only  in  fixed  proportions.  Chem- 
istry gives  us  the  knowledge  of  the  proportions 
in  which  the  different  substances  combine.  A 
general  idea  only  of  such  knowledge  necessary 
for  this  work  is  given.  The  mixture  of  all 
metals  by  fusion  forms  alloys,  hydrogen,  oxygen, 
chlorine,  bromine,  sulphur,  arsenic,  phosphorus, 
silicon,  etc.,  with  the  different  metals  enter  into 
the  various  compositions  of  ores  and  fluxes, 
which  to  a  certain  extent  the  assayer  must 
understand. 

A  test  of  ore  is  made  with  acids  or  heat,  usu- 
ally with  a  blow  pipe,  with  an  indefinite  amount 


8  PRACTICAL    MINING 

of  ore,  simply  to  determine  whether  the  ore  con- 
tains gold  or  silver  or  the  metals  sought  for. 
Testing  may  precede  assaying  to  enable  one  to 
know  what  fluxes  are  best  adapted  for  a  correct 
assay. 

Assays  are  made  by  wet  or  dry  processes,  i.  e., 
acids  and  chemicals  or  heat  with  the  proper 
fluxes  and  with  a  definite  quantity  of  ore  to  de- 
termine the  exact  amount  of  metals  it  contains 
per  ton  of  ore.  Lead  combined  with  oxygen  in 
the  exact  proportion  of  103^  parts  of  lead  by 
weight  to  8  parts  by  weight  of  oxygen  to  form 
litharge,  this  being  a  flux  for  most  classes  of  ores 
carrying  precious  metals.  The  melted  lead  gath- 
ers up  the  precious  metals  and  is  thrown  down 
by  carbon  which  is  a  reducer,  forming  a  lead 
button  in  the  bottom  of  the  crucible.  Under 
heat  the  affinity  of  carbon  for  oxygen  is  greater 
than  that  of  lead  for  oxygen.  Therefore  if  lith- 
arge and  carbon  are  heated  together  the  carbon 
takes  the  oxygen  from  the  litharge  and  the  lead 
is  set  free  and.  goes  to  the  bottom  as  stated 
above.  One  grain  of  charcoal  reduces  30  grains 
of  lead  from  litharge.  Flour  contains  carbon  and 
hydrogen,  also  oxygen  and  nitrogen  and  conse- 
quently is  a  reducer,  but  one  grain  of  flour  will 
only  throw  down  14  grains  of  lead.  Hence 
double  the  amount  of  flour  must  be  used  in  an 


PRACTICAL   ASSAYING  9 

assay.  I  prefer  the  flour  for  assaying  because  it 
is  more  convenient  to  procure  and  is  cleaner  and 
in  a  finer  powder. 

Nitre  consists  of  nitrogen,  oxygen  and  potas- 
sium, and  when  heated  gives  off  its  oxygen. 
When  sulphur  is  present,  the  oxygen  combines 
with  it,  and  the  sulphur  is  carried  off,  because 
the  affinity  is  stronger  for  the  sulphur,  so  that 
nitre  is  used  in  the  assay  of  sulphurets  to  carry 
off  the  sulphur,  melted  lead  having  a  strong  affin- 
ity for  oxygen  which  it  takes  from  the  air, 
when  the  door  or  opening  to  the  muffle  is 
open  to  admit  it  and  the  lead  is  oxydized  and 
part  of  it  goes  off  in  fumes  and  part  is  absorbed 
by  the  bone-ash  of  which  the  cupel  is  composed. 
Gold  and  silver  do  not  combine  with  oxygen, 
hence  when  the  lead  button  is  cupelled,  the  gold 
and  silver  remain. 


OF  THR  A 

UNIVERSITY  ) 


FORMATION. 

This  question  is  of  the  utmost  importance  and 
requires  considerable  study,  but  a  general  idea 
may  be  given  to  help  the  miner  or  prospector 
in  his  search  for  gold,  and  requires  a  technical 
knowledge  of  mineralogy.  By  technical  miner- 
alogy I  mean  only  that  amount  of  mineralogical 
knowledge  which  will  enable  the  prospector  to 
recognize  the  valuable  minerals  and  metals  and 
to  trace  them  by  the  formation  in  which  they  are 
most  likely  to  be  found.  This  forms  but  a  small 
part  of  the  whole  subject  of  mineralogy  as  a  sci- 
ence. It  is  therefore  important  that  the  prospec- 
tor should  be  able  to  distinguish  many  kinds  of 
rocks,  to  guide  him  or  to  check  him  in  his  ex- 
ploration. 

The  formations  forming  the  gold  belts  are  en- 
tirely different  in  different  countries  or  districts, 
hence  the  knowledge  of  the  formation  in  Oregon 
or  Arizona  will  not  assist  the  prospector  in  Cal- 
ifornia or  any  other  territory  except  in  a  very 
general  way.  A  man  may  be  an  expert  on  the 
Mother  Lode  in  California  and  know  nothing  of 
the  formation  in  Colorado.  One  thing,  however, 
may  be  settled  for  any  country  or  district,  and 
that  is  where  veins,  lodes,  or  vein  matter  is 


12  PRACTICAL    MINING 

found  in  a  contact  or  fissure,  i.  e.,  a  vein  between 
adjacent  bodies  of  dissimilar  rock,  where  gold  is 
found  in  these  formations  it  is  the  very  best  evi- 
dence of  the  existence  of  a  permanent  ledge,  and 
the  prospector  can  begin  his  development  with  a 
certain  degree  of  certainty. 

ROCKS. 

Rocks  may  be  classed  in  four  great  groups, 
described  as  follows:  Superficial  rocks,  Sedi- 
mentary rocks,  Igneous  rocks  and  Metamorphic 
rocks . 

FIRST — THE  SUPERFICIAL  ROCKS.  These  are 
composed  chiefly  of  clay,  sand  and  gravel  and 
lie  in  irregular  beds  and  unconsolidated. 

SECOND — SEDIMENTARY  ROCKS.  These  are 
conglomorate  sandstone,  shale  and  limestone 
which  have  been  deposited  by  the  water  and 
have  usually  become  hard. 

THIRD — IGNEOUS  ROCKS.  These  are  rocks 
wrhich  have  been  thnrvvn  up  from  a  molten  con- 
dition through  crevices  and  fissures  and  cooled 
where  they  have  formed  dikes  and  veins.  Some- 
times they  pour  out  of  cracks  and  volcanoes  and 
flow  over  the  surface  as  lava  and  afterwards  be- 
come scattered  and  broken  up  by  water  and 


PRACTICAL   ASSAYING  13 

streams.  The  most  abundant  of  these  are  gran- 
itic, grano-diorite,  granite -porphyry,  diabase, 
basalt,  augite-porphyrite,  augite-andesites  and 
hornblende. 

FOURTH — METAMORPHIC  ROCKS.  These  are 
altered  rocks  of  crystalline  texture  and  have 
been  so  changed  by  pressure  and  chemical  action 
that  the  mineral  particles  in  many  cases  re-crys- 
tallize and  are  understood  as  metamorphic,  crys- 
talline formations. 

We  will  now  give  the  names  and  a  brief  des- 
cription of  some  of  these  rocks. 

ALLYBYDENUM  is  a  sulphide  in  masses.  Has  a 
strong  metallic  lustre.  Color,  dead  grey.  Shows 
a  greenish  black  streak  on  a  common  piece  of 
broken  plate  or  china.  Easily  scratched  with  a 
nail.  Occurs  in  granite,  syenite  and  chlorite 
schists.  Sometimes  mistaken  for  graphite.  Its 
chief  use  is  for  the  manufacture  of  blue  colors. 
Value,  $12  per  pound. 

ANDESITE. — An  effusive,  porphyritic  rock. 
The  constituents  are  lime,  spar,  magnesia  and 
silica. 

ANTIMONY. — Resembles  galena  in  color  but  is 
crystalline  in  form  and  when  pure  looks  like  a 
mass  of  needle  points  melted  together.  Very 
often  galena  and  antimony  are  combined,  espe- 


14  PRACTICAL   MINING 

cially  iii  gold  and  silver  ores.  This  metal  mixed 
or  combined  with  galena  often  destroys  the 
value  of  a  lead  mine,  and  vice  versa. 

AUGITE. — A  dark  green  or  blackish,  composed 
of  iron,  schists,  and  magnesia;  lustre  vitreous; 
found  chiefly  in  volcanic  rock. 

BASALT.—  40  to  50  %  of  silica,  15  to  30  %  of 
alumina,  and  oxide  of  iron,  manganese,  lime, 
and  magnesia.  Color  is  black,  bluish  or  greenish 
shades  when  broken,  usually  drab  or  greyish 
brown  on  the  surface. 

BIRD'S  EYE  PORPHYRY  is  composed  of  feldspar 
and  specks  of  hornblende  and  mica  through  the 
rock  in  such  a  manner  as  to  form  little  specks 
resembling  birds'  eyes. 

CASSETERITE  or  TIN  ORE.— Tin  ore  is  usually 
an  oxide  and  contains  small  quantities  of  iron, 
copper,  manganese,  arsenic  and  silica  and  rarely 
any  lime.  The  ore  is  nearly  as  hard  as  quartz  and 
will  scratch  glass.  It  is  of  a  dark  brown  color, 
sometimes  almost  black;  when  scratched  with  a 
file  or  knife,  the  mark  turns  brown  or  light 
brown.  Zinc  does  the  same  when  found  in  other 
ores.  These  are  the  only  metals  that  the  fine 
powder  made  with  a  file  turns  brown.  It  is  usu- 
ally found  in  granite,  quartzite,  metamorphic 
sandstone  and  slaty  rock;  often  traced  with  black 


^  PRACTICAL   ASSAYING  15 

tourmaline.  It  is  sometimes  found  with  other 
ores  as  the  sulphide  of  tin  with  iron  and  copper. 
Looks  like  bell  metal  or  black  oxide  of  tin.  It 
is  found  in  granite  only  when  the  granite  con- 
tains chiefly  mica  and  quartz  or  mica  and  soda 
feldspar. 

COPPER  GLANCE. — Similar  to  the  above  in 
character  but  carries  a  much  larger  per  cent,  of 
copper.  The  fine  glance  carries  about  one-third 
metal.  Found  in  copper  ores. 

DIABASE.  —  An  intrusive  or  effusive  granular 
rock  composed  of  augite,  partly  or  wholly  con- 
verted into  fibrous  hornblende,  soda,  lime  and 
feldspar. 

DIORITE. — A  granular  intrusive  rock  com- 
posed piincipally  of  soda-lime,  feldspar  and 
hornblende. 

FELDSPAR  is  silicate  of  potash  and  alumina; 
silica  and  lime. 

GABBRO. — A  granular  intrusive  rock  consisting 
principally  of  dialage,  pyroxene,  together  with 
soda,  lime  and  feldspar. 

GABBRODIORITE. — This  term  has  been  used 
where  the  gabbro  areas  contain  primary  and 
secondary  hornblende. 

GALENA. — Bright  lead  color  having  a  metallic 
lustre  and  when  not  mixed  with  antimony, 


16  PRACTICAL    MINING 

breaks  in  cubes;  carries  silver  and  gold;  very 
often  found  in  gold  ores. 

GRANITE. — A  term  descriptive  of  rocks  com- 
posed of  silica,  feldspar  and  mica.  There  are 
different  classes  of  granite,  nor  are  they  alike  in 
color.  Some  granites  contain  no  mica  as  in 
graphic  granite.  Others  contain  black  mica 
stained  with  iron,  and  hornblende. 

GRANO-DIORITE.  —  This  is  also  an  intrusive 
rock  carrying  feldspar,  quartz,  biatite,  horn- 
blende and  mica. 

GRAPHITE  or  PLUMBAGO  or  BLACK  LEAD.— 
Soft  and  soils  the  fingers;  marks  on  paper;  color, 
gray  to  dark  blue,  nearly  black.  Found  chiefly 
in  crystalline  limestone  and  mica  schists  or 
graphite  schists. 

GYPSUM. — Composed  of  sulphuric  acid,  lime 
and  water.  When  it  is  pure  white  it  is  called 
alabaster;  when  transparent,  selenite;  when 
fibrous,  satin  spar;  and  when  burnt,  forms 
plaster  of  Paris. 

HORNBLENDE. — Contains  dark  or  black  crys- 
talline specks  or  crystals  consisting  essentially  of 
silica,  magnesia,  lime  and  iron. 

ITACOLUMITE. — A  quartzose  rock  that  is  more 
or  less  cemented  by  mica;  takes  its  name  from  a 
mountain  in  Brazil.  Diamonds  and  other  pre- 


PRACTICAL   ASSAYING  17 

cious  stones  are  found  in  this  and  other  similar 
rocks. 

KAOLIN. — A  peculiar  clay,  composed  of  silica, 
alumina,  pyroxide  of  iron  and  water.  It  is  used 
in  the  manufacture  of  porcelain  and  china;  found 
in  granitic  formations. 

LIMONITE. — A  brown  ironstone.  It  is  com- 
posed of  iron,  alumina  and  silex-,  and  sometimes 
manganese.  Belongs  to  the  iron  ores. 

MANGANESE. — It  occurs  as  a  black  or  red  ox- 
ide, often  with  red  or  brown  hematite;  very 
easily  pulverized.  When  dissolved  with  muriatic 
acid,  it  throws  off  chlorine  gas  which  can  be 
easily  detected  by  the  smell. 

MICA  SCHIST. — This  term  is  given  to  those 
laminated  rocks  composed  of  mica  and  quartz, 
manganese,  often  black,  colored  with  iron,  easily 
broken  up. 

MISPICKLE. — Often  mistaken  for  brittle  silver. 
It  occurs  usually  in  ores  that  are  regarded  as  re- 
bellious with  zinc  and  other  bases.  It  is  simply 
composed  of  arsenide  of  iron  and  iron  pyrites 
and  is  very  brittle. 

MICACEOUS"  QUARTZ  ROCKS. — These  are  not 
very  common.  Generally  found  in  a  granite 
formation;  sometimes  carry  gold. 


18  PRACTICAL    MINING 

PORPHYRY  is  feldspar,  quartzite,  talc,  mica, 
iron,  and  clay;  chiefly  feldspar  and  quartzite. 

PORPHYRITIC  GRANITE. — A  granite  with  a 
large  proportion  of  porphyritic  potash-feldspars. 
Color,  dark  green. 

PORPHYRITIC  QUARTZ. — A  rock  consisting  of 
quartz,  lime,  feldspar,  and  a  small  amount  of 
hornblende.  Often  found  in  contact  or  con- 
nected with  grano-diorite. 

PYROXENE. — Lustre  vitreous  inclining  to  res- 
inous, some  pearly.  Color  green  of  various 
shades  verging  from  white  and  grayish  white  to 
brown  and  black.  A  bi-silicate  of  lime,  magne- 
sia, protoxide  of  iron,  protoxide  of  manganese, 
and  sometimes  potash,  soda  and  oxide  of  zinc. 
Usually  twro  of  these  bases  are  present.  The 
first  three  are  the  most  common  but  l;me  is  al- 
ways present  and  in  a  large  percentage. 

QUARTZ  or  SILICA  is  combined  with  nearly 
every  other  kind  of  rock.  The  miner  must 
study  it  carefully,  as  nearly  all  the  gold  is  found 
connected  with  it  in  some  way.  A  few  general 
ideas  may  be  given  to  assist  the  prospector. 

When  found  in  ledges  or  loads  in  granite 
walls,  it  is  flinty  and  white  when  pure,  but  it  is 
nearly  always  stained  with  iron  and  often  car- 


PRACTICAL   ASSAYING  19 

ries  iron  pyrites.  It  breaks  in  chunks  like  sand 
and  granite  rocks,  and  when  gold  bearing,  the 
gold  is  found  in  pockets  or  bunches  and  not 
evenly  distributed  through  the  rock  as  it  is  found 
in  other  formations.  Sometimes  laminated  or 
stringer  quartz  is  found  in  granite  that  carries 
the  gold  principally  in  the  seams.  When  found 
in  a  contact  vein  or  "true  fissure"  it  is  of  a  more 
even  texture,  carries  lime  and  spar  and  is  much 
the  better  class  of  ore.  When  gold  or  pay  ore  is 
found,  it  is  more  evenly  distributed  through  the 
quartz  when  found  in  contact  of  slate  and  por- 
phyry. It  carries  enough  oxide  of  manganese  or 
slate  to  give  a  bluish  cast,  and  is  more  stratified. 
Often  carries  iron  pyrites  and  galena,  and  when 
galena  or  copper  stain  is  found  in  the  quartz,  it 
is  the  best  evidence  of  a  permanent  ledge  of  '4pay 
ore."  This  class  of  ore  when  found  in  Mexico, 
Arizona,  Nevada  and  Southern  California,  car- 
ries silver  and  often  leads  into  a  silver  mine  be- 
low the  water  line. 

RHYOUTE. — It  is  of  the  tertiary  age.  The 
essential  composition  is  alkali,  quartzose,  and 
hornblende. 

RED  OXIDE  OF  MANGANESE. — Looks  like  red 
ironstone.  At  first  sight  might  be  taken  for 
cinnabar. 


20  PRACTICAL    MINING 

SERPENTINE. — A  hydrous  silicate  of  magnesia 
combined  with  talc,  syenite,  and  hornblende, 
forming  rock  known  in  mining  regions  as  ( "ser- 
pentine." 

SIDERITE. — An  iron  carbonate;  about  62  per 
cent,  of  protoxide  of  iron  or  nearly  45  per  cent. 
of  pure  iron  and  from  15  to  20  per  cent,  of  man- 
ganese. Looks  like  black  ironstone  with  snail 
streaks  or  specks  of  white.  Color,  gray  to  black. 

SILVER  occurs  native  in  various  forms  usually 
branching  or  leaf-like  or  in  small  particles  that 
resemble  leaf  lead.  "  It  is  never  found  pure;  often 
carries  copper,  lead  and  gold;  it  is  always  malle- 
able and  can  easily  be  distinguished  from  mis- 
pickle  by  the  fact  that  it  can  be  cut  with  a  knife 
and  is  not  brittle.  Before  the  blowpipe  it  melts 
without  leaving  any  oxide  or  whiteness  around 
it  as  does  zinc,  antimony,  bismuth  and  tin. 

SILVER  GLANCE. — A  metallic  silver  combined 
with  iron  and  copper.  Has  the  appearance  of 
leaf  lead  nearly  black.  Often  occurs  pure  enough 
in  the  ore  to  be  cut  with  a  knife.  This  is  often 
connected  writh  copper  glance  found  in  rich  cop- 
per ores  with  hematite.  Usually  carries  from  20 
to  33  per  cent,  of  silver. 

SLATES. — There  are  several  kinds  of  these 
slates  which  should  be  carefully  studied.  All  of 


PRACTICAL   ASSAYING  21 

these  slates  are  sedimentary  or  water  washed  dis- 
integration and  are  found  as  mica  slate,  horn- 
blende slate,  clay  slate  or  argillaceous  shale  and 
bituminous  shale,  plumbago  schists  and  talcose 
slate.  Sometimes  trap  rock  and  trap  and  blue 
limestone  are  mistaken  for  slate,  but  all  slates 
have  cleavage  lines  and  break  in  planes  while 
the  trap  rock  breaks  irregularly  and  rough  and 
rings  to  the  hammer. 

TALC. — Composed  chiefly  of  silica  and  magne- 
sia, with  alumina  and  iron;  color  varies  from  a 
greenish,  to  a  yellowish  white  with  a  pearly  lus- 
tre, and  is  smooth  and  greasy  to  the  touch,  or 
soapy  if  moistened. 

ZINC  BLENDE. — Streaks  white  to  reddish 
brown.  Color,  resin  yellow  to  dark  brown  or 
black.  Occurs  in  rocks  of  all  ages  and  is  often 
associated  with  ores  of  lead  and  sometimes  those 
of  iron,  copper,  tin  and  silver. 

VEINS  OR  LODES. 

The  rocks  in  the  Auriferous  Belt  occur  in  very 
complex  associations,  but  we  have  to  deal  prin- 
cipally with  the  granites,  slates  and  schists,  and 
it  is  chiefly  in  these  schists  that  the  gold  or 
quartz  veins  are  found.  These  "gold  belts" 


22  PRACTICAL   MINING 

consist  principally  of  quartzite,  mica-schists, 
clay,  slate  and  limestone  lentils.  The  trend  of 
these  lodes  or  belts  is  generally  North-west  and 
South-east,  but  the  great  mass  of  granite  and 
igneous  rocks  have  been  intruded  among  these 
schists,  forming  irregular  bodies  which  interrupt 
the  regular  schistose  structure,  These  are  of 
the  group  that  forms  the  famous  "Mother  Lode" 
of  California. 

Converging  or  wedge  veins  are  numerous  and 
lie  between  the  divisions  of  stratified  rock,  as 
granite,  clay,  slate,  etc.  They  are  never  very 
long  and  sometimes  show  a  large  blowout  or 
cropping,  but  are  nearly  always  unreliable,  as  the 
wedge-like  space  between  the  walls  must  neces- 
sarily diminish  in  depth. 

GASH  VEINS. 

These  are  found  in  all  sedimentary    deposits. 

They  are  caused  by  shrinkage  of  the  particular 
stratum  in  which  they  exist  by  the  underlying 
igneous  conditions.  Ledge  matter  or  mineral 
deposits  may  be  found  in  these  veins  which 
sometimes  "go  down"  to  quite  a  depth  and  may 
be  rich,  but  they  are  not  very  long  and  thin  or 
pinch  out  at  the  ends.  Sometimes  they  are 
lapped  with  another  similar  vein  which  may  con- 


PRACTICAL    ASSAYING  23 

tinue  further.  A  number  of  these  veins  may  lap 
each  other  and  form  a  number  of  ledges  in  one 
claim  only  a  few  feet  apart,  but  they  seldom,  if 
ever,  go  down  to  any  great  depth  or  make  a 
large  or  permanent  mine. 

FISSURE  VEIN. — True  fissure  vein  quartz  in- 
variably shows  ribbon-like  stringers  parallel  to 
the  walls.  The  most  lasting  and  permanent  pay- 
ing mines  are  found  in  true  fissures  as  well  as  in 
the  contact. 

CONTACT  VEINS. —  A  quartz  ledge  or  other 
vein  matter  lying  between  two  walls  of  dissimilar 
rock,  as  slate  and  porphyry,  or  granite  and  dio- 
rite,  etc. 

CROSS  VEINS  are  transversely  fractured  fis- 
sures of  more  recent  origin.  They  are  often  pay- 
ing feeders  for  the  mineral  deposits  of  regular 
veins. 

BLANKET  LEDGES  are  those  that  lie  nearly 
horizontal  and  are  often  a  break  from  some  per- 
manet  vein  that  may  be  found  in  slides  which 
have  moved  them  from  their  fracture.  They  are 
seldom  very  large. 

DIKES  are  not  veins  and  are  generally  larger 
and  are  chiefly  composed  of  yellow  or  blue  col- 
ored feldspathic,  finely  crystallized,  igneous  rock, 
or  porphyry,  often  carrying  gold,  but  very  fine. 


24  PRACTICAL    MINING 

DEPOSITS. — Sometimes  quite  extensive  and 
must  have  been  concentrated  by  alluvial  water- 
washing,  or  precipitation  of  quantities  of  min- 
erals in  large  cavities  or  depressions  in  the  bed- 
rock. Those  of  the  volatile  and  condensable 
minerals  found  in  these  deposits  are  cinnabar 
and  sublimations  of  lead  and  antimony. 

ALLUVIAL  DEPOSITS  are  of  placer  and  gravel, 
sometimes  rich  in  gold  and  platinum. 

QUARTZ  LODES  and  vein  matter  often  well 
defined,  and  cropping  boldly  in  veins  and  spurs, 
cross-courses  and  small  dikes,  with  a  variety  of 
heave,  shift  or  slide  that  are  very  misleading  and 
must  be  carefully  studied  and  examined  in  order 
to  determine  what  relation  they  bear,  if  any,  to 
a  contact  or  "true  fissure." 

TESTS. 

TEST  FOR  SILVER. 

Powder  and  boil  a  small  quantity  of  the  ore  in 
nitric  acid;  allow  to  settle  and  put  in  a  few  drops 
of  muriatic  acid  when  it  will  immediately  form  a 
white  curdle  if  silver  is  present.  When  exposed 
to  sunlight  for  a  short  time,  this  white  curdle 
will  turn  dark.  Sometimes  the  whole  solution 
is  colored  with  iron;  if  so,  allow  it  to  stand  in 


PRACTICAL   ASSAYING  25 

the  test  tube  until  the  whitish  curdle  will  settle 
in  the  bottom  as  a  precipitate. 

TEST  FOR  SILVER  IN  COPPER  ORES. 

Boil  in  nitric  acid  as  above;  allow  it  to  settle. 
Put  into  the  soluton  a  polished  piece  of  copper. 
If  silver  is  present,  it  will  show  on  the  copper. 

WET  ASSAY  FOR  CpPPER. 

Pulverize  an  ounce  of  ore  finely;  place  in  a 
pint  dish  (agate  or  porcelain  lined)  and  boil  in 
four  ounces  of  muriatic  acid  until  the  acid  has 
nearly  all  evaporated,  leaving  the  mass  in  a 
pasty  condition.  Add  one-half  as  much  sul- 
phuric acid  and  boil  and  stir  for  a  few  minutes. 
Then  add  five  times  the  quantity  of  water.  Stir 
until  it  nearly  boils,  then  filter  the  whole.  The 
copper  is  now  all  dissolved  and  held  in  solution. 
To  this  solution  put  in  about  four  square  inches 
of  sheet  zinc  and  allow  it  to  stand  until  the  zinc 
has  entirely  dissolved.  All  the  copper  will  be 
precipitated  in  the  form  of  a  brown  or  nearly 
black  powder.  Filter  and  dry  when  the  powder 
may  be  weighed  and  melted  into  a  button. 

TEST  FOR  NICKEL. 

First  pulverize  one  ounce  of  ore.  Boil  in  3 
ounces  of  muriatic  acid  until  nearly  dry.  Add  8 


26  PRACTICAL    MINING 

or  10  ounces  of  water;  stir  and  boil.  Filter  and 
add  to  the  solution  caustic  potash  until  it  stops 
effervescing.  Filter  and  put  the  filtrate  in  a  cru- 
cible with  three  parts  of  soda  and  one  of  borax, 
and  melt.  Allow  it  to  cool  in  the  crucible  and 
find  the  button  in  the  bottom. 

TEST  FOR  IRON. 

Powder  and  dissolve  in  muriatic  acid  in  test 
tube  over  the  lamp.  Allow  it  to  cool  and  settle. 
Add  a  few  drops  of  ferro-cyanide,  when,  if  iron 
is  present,  it  will  immediately  turn  blue. 

TESTS  FOR  GOLD. 

MILLING  TEST. — This  may  be  satisfactorily 
made  in  the  following  manner.  Break  up  and 
powder  the  ore  to  pass  through  10  mesh,  not  less 
than  one-fourth  of  a  pound:  one  or  two  pound 
lots  are  better  if  your  muller  or  mortar  is  large 
enough.  For  this  purpose  a  Buck's  patent  muller 
is  the  best.  Now  dissolve  one  ounce  of  cyanide 
and  3  ounces  of  caustic  soda  in  five  gallons  of 
water:  then  add  one-half  teacup  full,  no  more,  of 
this  solution  into  the  water  or  muller  with  the 
ore,  and  half  a  thimble-full  of  mercury,  then  add 
one  pint  of  water;  grind  for  half  an  hour;  fill  the 
mortar  nearly  full  of  water,  turning  slowly  for 
fifteen  minutes.  Empty  the  whole  in  a  pan  and 


PRACTICAL   ASSAYING  27 

collect  the  mercury.  Be  careful  to  save  every 
particle.  Sometimes  it  is  very  hard  to  collect  all 
of  the  mercury.  In  such  cases  pour  off  all  the 
water  and  add  a  little  sodium  amalgam;  shake 
for  a  few  minutes,  when  it  will  all  collect  nicely. 
In  the  absence  of  sodium  amalgam  use  one  hand- 
ful of  dry  sand,  stirring  it  thoroughly  for  a  few 
minutes,  then  pan  it  as  usual,  when  the  mercury 
will  collect.  Now  dry  the  mercury  with  blot- 
ting paper,  put  it  in  an  evaporating  dish  or  any 
small  dish  that  will  stand  heat;  cover  with  two 
ounces  of  nitric  acid  and  boil  until  all  agitation 
ceases.  The  gold,  if  any,  will  be  found  in  a 
bead-like  form  at  the  bottom.  Pour  off  the  acid 
carefully,  rinse  with  rain  or  distilled  water;  dry 
over  a  lamp  and  weigh.  Calculate  the  weight  of 
gold  at  four  cents  per  grain.  If  one  pound  of  ore 
has  been  used,  multiply  by  2,000.  If  one-half 
pound  of  ore,  multiply  by  4,000,  and  so  on. 
This  gives  the  value  per  ton.  Follow  these  di- 
rections carefully  and  the  result  will  give  the 
exact  quantity  of  free  gold. 

CHEMICAL   ASSAY   FOR   GOLD. 

Take  a  carefully  prepared  sample  of  one  ounce 
of  ore,  ground  to  60  mesh;  put  into  an  enameled 
or  porcelain  dish  with  a  half  teacup-full  of  nitric 
acid;  stir  and  boil  until  the  fumes  are  steam 


PRACTICAL   MINING 

white.  Now  fill  the  dish  with  clear  water, 
stir  and  then  filter,  or  carefully  pour  off  the 
water;  add  a  little  lime  or  lye  with  more  water  to 
entirely  destroy  the  acid.  Be  sure  to  save  all  the 
pulp,  filter  or  pour  off  the  water  again;  rinse  all 
the  pulp  into  an  earthen  bowl;  now  add  a  few 
drops  of  mercury  and  grind  with  a  pestle  or  the 
bottom  of  a  long  bottle  for  half  an  hour,  save  the 
mercury  and  retort  with  acid  as  in  the  mill  test. 
Weigh  and  multiply  by  32,000;  the  result  will  be 
the  value  of  a  ton  of  ore.  The  gold  from  this 
test  must  be  weighed  on  the  bead  scales.  One 
bead  point  on  the  scale  with  one-tenth  of  a  grain 
rider  is  equal  to  $12.56  per  ton  of  ore. 

A    TEST    FOR    GOLD. 

A  simple  test  for  gold  may  be  made  by  first 
pounding  the  rock  to  a  fine  pulp  and  mixing 
with  it  twice  the  quantity  of  common  gun- 
powder and  water  into  the  constituency  of  thick 
mortar.  Press  it  into  the  form  of  a  brick  or  ball 
and  let  it  dry.  When  thoroughly  dry  place  it  on 
a  shovel  or  flat  rock,  cover  with  a  few  chips  and 
set  fire  to  it.  When  the  fire  goes  out,  rake 
through  the  ashes  or  pan  them,  and  you  will 
find  a  gold  button  if  there  is  any  in  the  ore. 
This  test  will  not  succeed  if  the  ore  carries  much 
iron  pyrites  or  other  base  metals. 


PRACTICAL   ASSAYING  29 

TEST  FOR  MANGANESE. 

A  very  interesting  test  for  manganese  is  made 
as  follows.  Take  the  ore  supposed  to  contain 
manganese  and  powder  a  little  very  fine  and  dis- 
solve it  in  ^KMTattc  acid  over  a  gentle  heat;  then 
let  it  cool  and  settle.  This  solution  will  be  col- 
ored brown.  Now  dissolve  a  little  sal  soda, 
(common  washing  soda),  in  pure  water;  then  put 
a  little  of  the  brown  solution  into  a  test  tube  or 
saucer,  add  soda  solution,  when  it  will  instantly 
become  clear  and  nearly  water- white,  if  mangan- 
ese is  present.  If  curdled  and  dark  or  cloudy,  it 
is  iron,  and  not  manganese. 

TEST  FOR  RED  COPPER. 

Very  brittle;  does  not  froth  with  acid,  but  is 
dissolved  in  ammonia  and  turns  blue  in  a  few 
minutes.  Also  the  carbonates  of  copper  will 
turn  blue  when  dissolved  in  ammonia. 

TEST  FOR  ZINC. 

Powder  the  ore  and  throw  on  live  coals. 
Shows  a  brilliant  white  flame.  Moisten  a  piece 
of  charcoal  with  a  solution  of  cobalt  nitrate.  Put 
some  of  the  powdered  ore  on  the  moistened  char- 
coal and  heat  with  a  blow  pipe  or  over  the  forge, 
when  it  will  turn  to  a  deep  green. 


30  PRACTICAL    MINING 

BLACK  ZINC  BLENDE. 

Is  sometimes  found  so  pure  that  it  is  mistaken 
for  galena.  The  infallible  test  is  that  when 
scratched  with  a  knife  the  powder  of  galena 
turns  black  whilst  that  of  the  blende  turns  brown. 

TEST  FOR  FLUORSPAR. 
Is  composed  of  fluoric  acid  and  lime.  Throw 
a  piece"  in  a  hot  fire  on  a  forge,  when  it  will  fly 
and  crack  in  pieces.  The  pieces  of  the  pure 
fluorspar  after  a  strong  heat  will  show  a  phos- 
phorescent light  some  little  time  after  being 
taken  from  the  fire.  Once  seen  will  always  be 
remembered. 

TEST  FOR  LIME  AND  THE  CARBONATES. 

After  heating  to  nearly  a  white  heat,  will  slack 
in  water  and  wrhen  powdered  produces  a  some-* 
what  violent  effervescence  in  acids. 

TEST  FOR  MERCURY.— (CINNABAR.) 

Powder  the  ore,  mix  one  or  two  grains  with 
equal  parts  of  soda,  and  place  in  the  bottom  of 
the  test  tube.  Take  a  small  thin  piece  of  copper 
or  brass  about  two  inches  long  or  a  little  gold- 
leaf;  (the  gold  leaf  must  be  wrapped  around  a 
thin  piece  of  wire.)  Place  the  copper  inside  the 
test  tube  using  a  cork  to  hold  it  in  place — one 


PRACTICAL    ASSAYING  31 

inch  of  the  copper  extending  below  the  cork. 
Gently  heat  over  a  lamp  until  nearly  red  and 
allow  it  to  cool.  If  mercury  is  present  it  will 
show  on  the  copper,  brass  or  gold,  whichever 
may  be  used. 

TEST  FOR  TELLURIUM. 
Powder  and  moisten ;  heat  with  blow  pipe  on  a 
piece    of  white    porcelain;  now"  moisten  the  hot 
porcelain   with  sulphuric  acid.     Leaves  a  red  or 
scarlet  color. 

TEST  FOR  ARSENIC. 

Powder  the  ore  and  throw  on  to  coals  or  heat 
on  charcoal  with  a  blow  pipe.  Gives  off  the 
smell  of  garlic. 

TEST    FOR    LIME,  MAGNESIA   AND 

BARITA. 

It  cuts  or  scratches  with  a  knife.  Foams  or 
effervesces  with  nitric  acid.  It  dissolves  with 
effervescence  in  muriatic  acid,  and  if  pure,  that 
is,  not  mixed  with  other  matter,  the  solution 
will  be  colorless. 

TEST  FOR  GYPSUM.— (HEAVY  SPAR.) 

Is  scratched  with  quartz  or  a  knife.  Does  not 
dissolve  with  acids  and  has  no  smell  when 
heated.  When  ground  finely,  it  feels  like  starch. 


32  PRACTICAL    MINING 

TEST     FOR     NITRATES.  —  (CHILLY     NI- 
TRE,    ETC.) 

Flashes  when  thrown  on  live  coals.  It  will 
dissolve  in  water,  and  when  four  parts  of  this  so- 
lution and  one  part  of  sulphuric  acid  and  one 
part  of  salt  are  mixed  together  it  will  dissolve 
gold. 

PANNING  FOR  GOLD. 

The  prospector  and  even  the  practical  miner  is 
almost  invariably  deceived  in  the  value  of  gold 
he  gets  from  a  few  pieces  of  ore  in  the  pan  or 
horn.  In  the  first  place,  he  will  always  think 
that  the  piece  or  pieces  of  ore  he  took  to  sample 
or  pulverize  is  not  nearly  as  much  as  it  really  is. 
He  will  think  he  has  pounded  up  about  an  ounce 
when  it  is  nearer  three  ounces,  and  should  al- 
ways weigh  the  sample  before  crushing,  and  then 
he  may  form  some  reasonable  estimate  of  the 
value  of  ore  per  ton  by  the  amount  of  gold  in  the 
pan,  if  he  has  been  careful  to  have  even  ounces, 
as  two  or  four.  Now  after  he  has  saved  a  few 
colors  they  always  look  to  be  more  than  there 
really  is.  Especially  if  the  gold  is  fine,  one  may 
really  think  there  is  $10  per  ton  when  there  is 
not  $5.  It  takes  very  many  fine  particles  of 
gold  to  make  one  cent.  To  illustrate  how  very 


PRACTICAL    ASSAYING  33 

fine  it  can  be,  one  grain  of  gold  is  worth  four 
cents,  and  this  one  grain  can  be  hammered  into 
a  leaf  of  gold  containing  75  square  inches. 

One  50,700th  part  of  one  grain  can  be  seen  by 
the  eye,  and  gold  is  found  in  talcose  slate  so 
very  fine  that  it  would  take  enough  of  these  par- 
ticles to  cover  four  inches  square  to  make  one 
cent,  so  unless  the  gold  is  coarse,  one  may  easily 
be  deceived  as  to  the  amount  or  value  of  gold  in 
a  ton  of  ore,  if  you  will  carefully  pan  the  gold 
from  ^  pound  of  ore  and  then  collect  it  with 
mercury,  as  in  the  mill  test  given  on  page  26; 
then  the  gold  can  be  weighed  and  calculated 
with  some  degree  of  certainty. 

ASSAYING. 

This  work  is  not  intended  for  those  who  wish 
to  fit  up  an  assay  office  for  a  permanent  business, 
in  which  case  they  would  require  a  full  and  com- 
plete laboratory.  I  will  endeavor  to  describe  and 
explain  how  to  make  satisfactory  assays  and  prac- 
tical tests  on  the  ground,  at  the  mine,  or  over 
the  forge.  An  outfit  for  the  assay er  may  be 
very  elaborate  and  expensive  but  for  the  purpose 
of  this  work  only  the  few  implements  actually 
necessary  are  mentioned.  First,  a  small  port- 
able carbon  or  coke  furnace.  It  can  be  bought 
for  $12  or  $15.  In  a  coal  furnace  the  muffle  will 


34  PRACTICAL    MINING 

be  included.  With  the  carbon  furnace  it  will  be 
necessary  to  have  a  muffle  furnace  separate. 
This  muffle  furnace  will  cost  about  $23,  but  for 
the  many  wrho  may  not  possess  either  of  these, 
satisfactory  assays  may  be  made  with  an  ordi- 
nary blacksmith's  forge.  Nearly  everything  re- 
quired for  practical  tests  and  assays  may  be  had 
at  almost  every  small  town,  or  may  be  carried  in 
a  gripsack.  The  only  expensive  things  required 
are  the  scales  for  weighing  the  prills  or  beads. 
There  are  small  pocket  scales  that  will  answer 
every  purpose,  and  can  be  bought  for  $12,  but  if 
one  has  no  scales,  the  prills  or  beads  from  the 
assay  and  the  gold  from  the,  mill  test  must  be 
saved  in  small  bottles,  and  numbered,  to  be 
weighed  when  convenient. 

For  assaying  one  must  have  crucibles  to  hold  8 
ounces.  I  use  No.  9  Denver;  they  cost  8  cents 
each.  (Following  is  given  a  list  of  the  more  im- 
portant things.) 

The  cupels  should  be  one  and  one-half  inches, 
and  cost  30  cents  a  dozen.  One-half  inch  test 
tubes  5  inches  long.  For  a  drying  cup  a  broken 
saucer  will  answer.  Evaporating  dishes  3  and  4 
inches.  These  cost  35  cents,  and  will  stand 
heat.  A  muffle  costs  one  dollar. 

A  substitute  for  a  muffle. — Take  a  piece  of  4 
or  5  inch  'iron  pipe  or  an  old  mercury  flask  or  a 


PRACTICAL   ASSAYING  35 

crucible;  any  one  of  these  will  answer  the  pur- 
pose. A  mortar. — A  good  substitute  for  a  mor- 
tar is  a  piece  of  2  or  8  inch  gas  pipe  8  inches 
long.  For  a  pestle  any  old  steel  drill.  Sieves 
6J  mesh  and  10  mesh.  One  pair  of  small  pulp 
scales  to  weigh  the  ore;  any  scales  that  will 
weigh  a  half-ounce  or  more,  will  answer. 

On  page  36  is  a  cut  of  a  pulp  scale  that  any 
one  can  make  in  an  hour,  that  will  answer  for 
weighing  from  one-sixteenth  of  an  ounce  to  two 
ounces  or  more  of  ore  for  assaying.  A  glance  at 
the  cut  will  show  how  it  is  made.  A  scale  bar  is 
made  out  of  a  thin  strip  of  board  \  inch  wide, 
narrowed  down  at  the  ends  a  little,  and  a  needle 
put  through  the  middle  just  above  the  center  line; 
piece  of  tin,  3  inches  long  and  1  inch  wide,  more 
or  less,  with  the  ends  bent  up  square,  as  shown, 
for  the  needle  to  rest  on;  and  the  cover  of  a  small 
tin  can  be  fastened  to  one  end  to  hold  the  ore, 
and  a  small  bar  of  lead  weighing  just  two 
ounces,  bent  so  as  to  straddle  the  bar.  Place  the 
lead  weight  close  to  the  needle,  just  so  it  will 
balance  the  pan  at  the  other  end.  Mark  the  bar 
at  the  lead,  and  divide  or  rule  it  from  the  bal- 
ance to  the  end  into  32  lines  or  divisions,  to  the 
end.  Now  when  the  lead  weight  is  at  the  end 
it  should  balance  with  2  ounces  of  ore  in  the  pan. 


36 


PRACTICAL    MINING 


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PRACTICAL    ASSAYING  o7 

A  common  earthen  bowl  will  do  for  mixing  the 
assay,  or  it  may  be  mixed  on  a  piece  of  strong 
paper  with  a  spatula  or  ordinay  table  knife. 
One  pair  of  crucible  tongs  and  one  pair  of  cupel 
tongs.  —  These  may  be  made  with  a  piece  of 
quarter-inch  wire  three  feet  long.  Flatten  the 
ends,  bending  them  together.  Some  of  the 
smaller  blacksmith's  tongs  will  answer.  An  iron 
mould  is  necessary  for  pouring  the  assay  into,  if 
you  desire  to  save  the  crucible  for  another  assay; 
but  if  you  have  no  mould,  remove  the  crucible 
from  the  fire,  jar  it  lightly  to  settle  the  lead  and 
stand  it  where  it  will  cool  and  then  break  and 
find  the  lead  button  at  the  bottom  which  must 
be  cleaned  of  all  the  slag,  when  it  is  ready  for 
the  cupel. 

If  working  with  a  coke  or  charcoal  furnace  or 
forge,  first  get  a  good  bed  of  glowing  coals.  Set 
in  the  crucibles,  hold  them  in  place  until  the 
coal  is  placed  firmly  around  them.  The  cru- 
cibles must  always  be  covered  with  the  crucible 
covers  in  order  to  keep  everything  out.  Open 
the  blast  and  heat  until  nearly  white.  Remove 
the  cover,  and  if  the  slag  has  quit  boiling,  looks 
smooth  and  settled,  it  is  ready  to  pour  into  the 
mould.  When  nails  are  used,  they  must  be 
taken  hold  of  with  the  tongs,  tapped  lightly 
against  crucible  side  and  removed;  then  pour. 


38  PRACTICAL    MINING 

CUPELLATION. 

Cupels  may  be  made  of  bone  ash  together  with 
the  proper  moulds,  but  when  a  few  are  wanted  it 
is  preferable  to  buy  them.  The  proper  size  is 
one  and  one-half  inches  for  the  ordinary  assay. 
If  you  have  a  regular  furnace  the  muffles  will  be 
provided  and  the  work  is  simple.  The  cupels 
are  placed  inside  the  muffle  as  many  as  may  be 
required,  and  then  brought  to  a  red  heat 
when  you  take  out  the  tongs  and  place  the  lead 
button  inside  the  cupel,  carefully  noting  the  po- 
sition in  order  to  identify  each  assay.  Close  the 
muffle  and  increase  the  heat  to  a  bright  red  or 
until  the  lead  is  well  melted,  when  it  is  opened  a 
little  to  admit  air.  The  lead  now  appears  lumi- 
nous; rainbow  colors  are  circling  over  it.  Air 
should  be  admitted  at  this  point  to  increase  the 
oxidization. 

When  the  fumes  are  seen  rising  from  the  lead 
it  must  be  kept  in  that  condition  until  the  lead 
has  enterely  disappeared,  when  the  cupel  is  re- 
moved and  cooled.  The  prill  is  then  ready  to  be 
weighed  and  parted. 

PARTING. 

Silver  is  soluble  in  nitric  acid.  Gold  is  not, 
but  the  bead  to  be  parted  must  contain  at  least 
twice  as  much  silver  as  gold,  and  should  be  flat- 


PRACTICAL   ASSAYING  39 

tened  to  a  thin  sheet  and  put  in  test  tube  and 
boiled  in  nitric  acid  until  the  red  fumes  cease, 
and  the  acid  clears;  and  the  particles  of  gold,  if 
any  is  seen  at  the  bottom,  as  brown  powder. 
Now  pour  off  the  acid  and  fill  the  tube  with  pure 
or  distilled  water,  and  rinse  once;  then  fill  with 
water,  and  place  the  dry  cup  or  saucer  over  the 
tube  to  hold  the  water,  and  invert  the  whole, 
still  holding  it  firm,  allowing  the  gold  to  settle 
in  the  cup,  and  let  the  water  off  gradually.  Now 
dry  and  weigh  the  gold.  Having  first  weighed 
the  bead  from  the  assay  subtract  the  weight  of 
gold  from  the  weight  of  the  whole  bead  and  you 
have  the  amount  of  silver  and  gold  in  the  assay, 
unless  it  is  known  that  the  ore  contains  two  or 
more  parts  of  silver,  to  one  of  gold,  a  weighed 
amount  of  pure  silver  should  be  added  to  the  as- 
say in  the  crucible,  and  deducted  from  the  bead 
weight. 

BEAD  SCALE. 

A  cheap  and  convenient  bead  scale  is  shown 
on  page  41.  Take  a  hard,  dry  piece  of  wood  6 
inches  long  and  ^  of  an  inch  thick  and  •§  of  an 
inch  wide  in  the  center  and  i  of  an  inch  wide 
at  each  end.  Bend  a  small  piece  of  tin,  or  thin 
brass  V-shaped,  and  fasten  to  the  right  end  as 
shown  in  the  cut  to  hold  the  weights,  and  fasten 


40  PRACTICAL    MINING 

to  the  other  end,  a  piece  of  tin  \  inch  square, 
made  a  little  cupping  to  hold  the  beads.  Now 
take  a  piece  of  1^  inch  wide  and  6  inches  long 
for  a  base.  Fasten  onto  each  side  of  this  base  a 
piece  3  inches  long  and  %  inch  square,  on  top  of 
these  (see  cut.)  Fasten  a  piece  of  glass  tubing 
filled  nearly  full  of  alcohol  corked  and  sealed,  on 
top  of  these  pieces  with  small  wire  staples,  as 
shown.  These  show  when  the  scale  is  level,  and 
serve  as  rests  for  the  ends  of  the  needle,  passing 
through  the  scale  beam  as  seen  in  the  cut.  This 
needle  must  be  put  exactly  in  the  middle  of  scale 
bar,  and  just  ^  of  an  inch  below  the  top.  Use  the 
regular  Troy  weights  from  10  grain  to  one-tenth 
of  a  grain,  with  a  one-tenth  rider  weight  to  use 
on  the  scale  bar  which  must  have  the  division 
lines  from  the  center  to  right  end.  Divided  into 
20  parts  with  the  figures,  1,  2,  3,  4,  5,  6,  7,  8,  9, 
on  the  tenth  divisions,  the  same  as  the  regular 
scales,  the  pan  making  the  tenth. 

WEIGHING. 

The  bead  is  taken  from  the  cupel,  placed  in 
left  hand  pan  of 'the  scales,  as  it  will  be  more 
convenient  to  use  the  weights  in  the  right  hand 
pan,  if  you  have  the  proper  bead  scale,  with 
riders.  The  beam  is  divided  into  20  parts, 
numbering  the  tenths,  1,  2,  3,  4,  5,  6,  7,  8,  9, 


PRACTICAL  ASSAYING 


41 


42  PRACTICAL    MINING 

the  pan  making  10.  Now  if  you  have  taken  240 
grains  for  the  assay,  and  have  the  Troy  weights, 
every  number,  or  tenth,  is  one  one-hundredth 
part  of  a  grain  and  is  called  a  "bead  point,"  and 
is  1.21  ounces  to  the  ton  of  2,000  pounds  of  ore, 
and  if  gold,  $25.12.  (See  table.) 

If  you  take  291.66  grains  of  ore  for  the  assay, 
every  bead  point  will  represent  one  ounce  to  the 
ton  of  ore,  and  if  gold,  $20.67. 

FLUXES. 

LITHARGE. — A  lead  oxide,  8  to  10  cents  per 
pound.  It  is  an  oxidizer  or  desulphurizer;  that 
is,  it  oxidizes  the  iron  and  destroys  the  sulphur 
and  is  a  source  of  lead  which  takes  up  the  gold 
and  silver  in  the  ores.  It  is  a  flux  because  re- 
fractory substances  are  melted  with  litharge  at  a 
moderate  heat.  It  fluxes  most  rock^,  earth  and 
metal  oxides.  A  desulphurizer,  because  it  burns 
the  sulphur. 

SODA. — Common  baking  soda,  4  cents  a 
pound.  It  fluxes  quartz  and  some  metal  oxides, 
desulphurizes  galena,  antimony  and  bismuth. 

BORAX. — 8  cents  per  pound.  Fluxes  clay, 
lime,  magnesia,  slate. 

BORAX  GLASS. — 65  cents  per  pound.  Fluxes 
the  same  as  borax  but  does  not  swell.  To  pre- 


PRACTICAL   ASSAYING  43 

pare  it,  melt  it,  allow  it  to  cool  in  thin  pieces 
and  grind  to  powder.  One  part  by  weight  is 
equal  to  two  of  undried  borax. 

GLASS. — Common  bottle  or  window  glass. 
Pulverize  and  grind  finely.  Used  in  assays  con- 
taining much  lime,  clay,  etc.,  but  not  quartz. 
Useful  in  an  assay  where  much  litharge  or  nitre 
is  used  to  protect  the  crucible. 

NITRE. — 15  cents  per  pound.  A  powerful  ox- 
idizer;  destroys  the  sulphur;  will  oxidize  all  met- 
als excepting  gold  and  some  of  the  platinum 
group. 

SULPHUR. — Used  in  certain  kinds  of  assays,  as 
copper,  to  prevent  the  copper  entering  the  lead 
button.  The  copper  will  be  converted  into  sul- 
phurets. 

IRON. — (Nails  or  wire.)  A  desulphurizer  for 
galena  and  silver  ores  with  sulphur,  not  for  sul- 
phurets  of  iron,  copper  and  zinc. 

SALT. — Used  because  it  becomes  very  fluid. 
Serves  as  a  cover  to  exclude  air,  also  to  wash  the 
sides  of  the  crucible. 

SHEET  LEAD. — 25  cents  a  pound.  Tea  lead 
will  answer. 

FLOUR.  —  A  reducer;  reduces  the  litharge  into 
lead.  One  part  by  weight  of  flour  reduces  fifteen 
parts  of  lead. 


44  PRACTICAL    MINING 

CHARCOAL. — A  still  better  reducer  than  the 
above,  as  it  throws  down  30  parts  of  lead  by 
weight  to  one  part  of  charcoal. 

ACIDS. — Nitric  40  cents  per  pound,  muriatic 
and  sulphuric. 

DISTILLED  WATER. — Filtered  rain  water  will 
answer. 

BLACK  FLUX. — A  mixture  of  charcoal,  potas- 
sium carbonate;  one  ounce  of  powdered  charcoal 
and  8  ounces  pulverized  potassiu  mcarbonate, 
thoroughly  mixed  and  kept  dry. 

DRESSING  FOR  DIFFERENT  ORES. 

It  must  be  remembered  that  soda  is  a  flux  for 
quartz  and  galena,  borax  for  earths  and  metal 
oxides  generally,  litharge  for  all.  I  give  a  few 
samples  of  dressings  for  general  use.  Charcoal 
and  flour  are  reducers.  Charcoal  has  double  the 
strength  of  flour;  either  can  be  used. 

Quartz: 

Ore One  part. 

„    Litharge Three  parts. 

Soda.  .  .  .One  and  one-half  parts. 

Borax One-half  part. 

Flour One-eighth  part. 

or  Charcoal. .  .  .One-twelfth  part. 
Cover  with  salt. 


PRACTICAL   ASSAYING  45 

Mix  the  litharge  with  the  ore  first,  then  mix 
all  together  thoroughly,  and  after  placing  in  the 
crucible  cover  with  the  salt.  The*  crucible 
should  not  be  more  than  two- thirds  full. 

Quartz  carrying  not  more  than  three  per 
cent,  of  sulphurets: 

Ore -One  part. 

Litharge Three  parts. 

Soda One-half  part. 

Borax One  part. 

Charcoal One-eighth  part. 

Cover  with  borax  and  salt. 

Rock  carrying  iron  pyrites  and  galena  from 
two  to  ten  per  cent.: 

Ore One  part. 

Litharge Three  parts. 

Soda One  part. ' 

Pearl  ash One-half  part. 

Borax One  part. 

Charcoal One-eighth  part. 

Cover  with  salt  with  two  or  three  twelvepenny 
nails,  according  to  the  amount  of  sulphurets 
contained  in  the  ore.  The  nails  are  stuck  down 
through  the  dressing,  heads  up.  They  serve  to 
throw  down  the  lead  and  silver  and  take  up  the 
sulphur. 


46  PRACTICAL    MINING 

Ore  carrying  galena,    copper,  zinc   and  other 
bases : 

Ore One  part. 

Litharge Five  parts. 

Soda Three  parts. 

Pearl  ash One  part. 

Charcoal  .  .  .  .One-sixteenth  part. 
Cover  thickh-  with  salt  and  add  three  or  four 
twelvepenny  nails. 

Silver  ores  carrying  galena: 

Ore One  part. 

Soda Two  parts. 

Pearl  ash One  part. 

Charcoal  ....  One-sixteenth  part. 

Cover  with  borax. 

Quartz  rock  carrying  five  to  ten  per  cent,  sul- 
phurets: 

Ore One  part. 

Litharge Four  parts. 

Soda  ..'... One  part. 

Pearl  ash One-half  part. 

Borax One  part. 

Charcoal One-tenth  part. 

Cover  with  salt  and  borax  mixed. 
Ore  containing  arsenical  pyrites  or  arsenide  of 
iron,  five  to  twenty  per  cent.: 

Ore. One  part. 

Soda Two  parts. 


PRACTICAL   ASSAYING  47 

Litharge Four  parts. 

Pearl  ash One  part. 

Charcoal One-twlfth  part. 

Cover  with  borax;  stick  one  twelvepenny  nail 
in  the  center. 

Antimony: 

Ore One  part. 

Soda Four  parts. 

Cyanide  of  potassium  Two  parts. 
After  charging  the  crucible,  add  a  few  grains 
'of  charcoal. 

Galena:  * 

Ore One  part. 

Soda Four  parts. 

Pearl  ash One  part. 

Charcoal  ....  One-sixteenth  part. 

Ordinary    ores    carrying    quartz,    clay,    lime, 
iron,  etc. : 

Ore One  part. 

Litharge Three  parts. 

Soda One-half  part. 

Pearl  ash One-half  part. 

Borax One  part. 

Charcoal One- twelfth  part. 

A  little  salt  to  cover,   and  one-third  part  of 
borax  on  top. 


48  PRACTICAL    MINING 

For  the  most  refractory  ore: 

Ore One  part. 

Litharge Sixteen  parts. 

Soda Two  parts. 

Borax-glass One  part. 

Charcoal One-sixth  part. 

Salt  to  cover. 

Concentrated  pyrites: 

Ore One  part. 

Litharge Eight  parts. 

Soda Eight  parts. 

Glass Four  parts. 

Lead: 

Ore One  part. 

Soda Four  parts. 

Borax One  part. 

Flour,  by  weight,  One-sixth  part. 

Bismuth: 

Ore. .  .  .  , One  part. 

Soda Four  parts. 

Borax-glass One-half  part. 

Flour One-twelfth  part. 

Salt  to  cover. 
Tin: 

Ore One  part. 

Soda •  , .  Three  parts. 

Cyanide  of  potassium  Two  parts. 


PRACTICAL   ASSAYING  49 

Assay  for  pure  concentrates  or  ore,  any  very 
heavily  sulphurated  ore  or  nearly  any  of  the  very 
base  ores: 

Take  240  grains  of  ore  or  the  assay  ton  of 
291.66  grains  of  ore;  pulverize  to  60  mesh;  mix 
thoroughly  with  double  the  quantity  of  nitre, 
(salt  peter).  Put  into  a  crucible  so  large  as  not 
to  more  than  half  fill  it.  Place  in  a  moderately 
hot  fire  and  after  complete  fusion  stir  it  in  the 
crucible  with  a  hot  iron  rod  or  wire  three  or  four 
minutes,  then  add  quickly  with  a  long  scoop  or 
ladle,  the  flux,  it  having  been  prepared  before- 
hand, as  follows:  \  ounce  of  litharge,  one  ounce 
of  soda  and  six  grains  of  finely  pulverized  char- 
coal; and  cover  the  crucible  and  incease  the 
heat,  when  it  should  melt  in  fifteen  or  twenty 
minutes.  When  melted  take  the  crucible  and 
tap  lightly  to  settle  the  lead,  and  let  it  remain  in 
the  crucible  until  cool;  then  break  the  crucible, 
extract  and  clean  the  button,  cupel  and  weigh. 

METALS  THAT  ARE  DISSOLVED  IN  ACID. 

Nitric  acid  disssolves  silver,  copper,  iron,  bis- 
muth, zinc  and  mercury. 

Sulphuric  acid  dissolves  silver,  copper,  bis- 
muth, zinc,  tin  and  antimony. 

Hydrochloric  or  muriatic  acid  dissolves  iron, 
zinc,  bismuth,  and  antimony  if  powdered. 


50  PRACTICAL    MINING 

One  part  of  nitric  acid  and  two  parts  muriatic 
acid  dissolves  gold,  platinum,  copper,  iron,  silver, 
zinc  and  bismuth;  and  if  diluted  with,  will  dis- 
solve lead.  Lead  is  not  dissolved  in  nitric  acid, 
but  will  be  converted  into  a  white  powder. 

A  solution  of  caustic  potash  dissolves  zinc,  tin, 
and  aluminum. 

A  solution  of  cyanide  of  potassium  dissolves 
the  following  metals  out  of  finely  pulverized  ore: 
gold,  silver,  zinc,  copper,  lead  and  aluminum. 
It  will  act  more  rapidly  when  combined  with 
peroxide  of  soda. 

TESTING  ORES  WITH  ACIDS. 

Many  very  satisfactory  tests  can  be  made  with 
acids  with  very  little  trouble,  the  outfit  costing 
only  a  few  dollars,  and  can  be  carried  in  a  small 
chest  or  even  a  grip  sack,  the  material  actually 
necessary  consists  of  the  following: 

1  Ib.  C.  P.  nitric  acid. 

1  Ib.  C.  P.  muriatic  acid. 

1  Ib.  sulphuric  acid. 

\  Ib.  cyanide  of  potassium  (dry). 

1  bottle  caustic  soda,  in  sticks  (pure). 

1  small  porcelain-lined  dish. 

2  small  evaporating  cups. 
•   dozen  test  tubes. 


PRACTICAL   ASSAYING  51 

1  funnel,  some  filter  paper  and  some  blotting 
paper. 

1  Ib.  mercury  and  £  Ib.  sodium  amalgam. 

1  small  bottle  of  ammonia. 

\  Ib.  ferrocyanide;  a  few  thin  strips  of  copper 
and  zinc. 

1  Ib.  sal  soda  (common  washing  soda). 

The  above  outfit  will  enable  one  to  make  the 
milling  test  for  free  gold,  the  copper  assay  and 
the  chemical  tests  given  in  this  work,  as  well  as 
many  qualitative  tests  for  gold,  silver,  copper, 
lead,  mercury,  iron,  bismuth,  manganese,  anti- 
mony and  nickel.  If  the  ore  contains  iron  py- 
rites, sulphate  of  copper,  arsenic  or  zinc,  it  is 
well  to  powder  and  roast  the  ore  before  the  acid 
is  added,  but  if  one  ounce  or  less  is  taken  for  the 
test,  and  this  powdered  to  90  or  100  fine,  then 
nitric  acid  will  do  the  work. 

Put  a  little  of  the  powdered  ore  into  a  test 
tube,  or  one  of  the  evaporating  dishes;  if  a  test 
tube  is  used,  take  as  much  ore  as  will  lay  on  a 
ten  cent  piece.  If  a  dish  is  used,  \  ounce  of  the 
powdered  ore  may  be  used.  The  acid  used  in 
test  tube  should  fill  the  tube  not  more  than  1^ 
inches  above  the  ore;  if  a  dish  is  used  1  ounce 
of  nitric  acid  with  a  very  little  water  may  be 
added  to  the  ore  and  heated  gently  over  a  lamp 
10  or  15  minutes,  or  until  any  violent  action 


o2  PRACTICAL    MINING 

ceases,  then  let  it  stand  until  cool  and  settled. 
Now  pour  a  little  of  this  solution  into  a  test 
tube,  and  add  and  as  much  muriatic  acid.  Now  if 
the  ore  carries  silver,  it  will  be  seen  as  a  whitish 
curdle  or  white  precipitate  of  chloride  of  silver. 
If  lead  is  present  it  will  be  thrown  down  as  a 
white  precipitate,  or  powder;  mercury  will  show 
the  same  as  silver,  but  mercury  and  silver  are 
not  found  in  the  same  ore.  Now  if  a  precipitate 
is  found  and  settled  at  the  bottom,  carefully  pour 
off  the  clear  solution  and  add  a  little  ammonia  to 
this  precipitate  and  shake  it  a  little  in  the  tube 
and  note  the  result. 

If  the  white  -precipitate  is  dissolved,  it  is  sil- 
ver. If  blackened,  it  is  chloride  of  mercury.  If 
it  still  remains  unchanged,  it  is  lead.  A  test  for 
antimony  is  made  the  same  way,  dissolving  first 
in  nitric  acid,  and  adding  muriatic;  let  it  settle 
clear  as  before  and  introducing  a  piece  of  zinc, 
if  it  is  antimony  a  black  precipitate  will  be  seen. 
If  the  ore  to  be  tested  carries  iron,  copper,  and 
other  metals,  first  thoroughly  dissolve  the  pow- 
dered ore  in  nitric  acid  by  heating;  let  cool  and 
settle.  Now  try  a  little  of  this  solution  in  a  test 
tube,  by  adding  as  much  dilute  sulphuric  acid, 
white  precipitate,  shows  lead.  Add  an  excess  of 
ammonia  to  some  of  the  original  solution,  and  a 
blue  color  shows  copper,  or  nickel. 


PRACTICAL    ASSAYING  53 

Red  color  shows  peroxide  of  iron.  By  adding 
muriatic  acid  to  this  solution,  and  introducing 
the  point  of  a  knife,  a  coating  of  copper  will 
form  on  the  blade  if  copper  is  present.  Again 
add  an  excess  of  potash  to  the  first  solution  and 
note  the  reaction.  Blue  shows  the  presence  of 
colbalt;  light  green  of  nickel,  brown  of  iron; 
white  of  zinc;  yellow  of  mercury. 

CONCENTRATOR. 

My  improved  carpet  concentrator  (see  cut,  page 
54),  is  one  of  the  most  effective  and  least  expen- 
sive used,  and  does  not  require  power.  "A"  is 
tank  6  feet  wide  and  16  feet  long.  In  it  is 
placed  a  box  29  inches  square  and  15  feet  5 
inches  long,  hung  on  gudgeons  at  each  end,  to 
run  in  boxes  on  the  outside  of,  and  at  the  end  of 
tank  "A,"  as  shown  in  the  end  view  (fig.  2), 
allowing  it  to  revolve.  This  inside  box  is  made 
by  cutting  end  pieces  out  of  2-inch  plank  ex- 
actly 27  inches  square.  Now  nail  on  one-inc'h 
boards  16  feet  long  to  form  the  box.  Let  the 
inch  board  project  over  the  two  sides  two  or 
three  inches  to  form  a  trough  or  sluice,  and  nail 
strips  one  by  three  on  the  other  two  sides  for  the 
sluice;  now  cover  these  sides,  which  will  be  just 
27  inches  inside  the  sluice,  with  Brussels  carpet; 


54 


PRACTICAL    MINING 


PRACTICAL   ASSAYING  55 

the  whole  is  placed  below  the  plates  "D"  as  any 
other  concentrator,  with  the  same  pitch  or  in- 
cline as  the  copper  plates.  Now  the  pulp  is  car- 
ried from  the  plates  to  the  carpet  with  a  short 
moveable  apron.  Then  the  pulp  flows  over  the 
carpet,  and  the  sulphurets,  and  heaviest  particles 
settle  in  carpet,  and  are  washed  off  into  tank 
"A"  as  the  box  revolves,  in  the  water  in  the 
tank.  Now  as  the  carpet  becomes  filled  with 
concentrates  a  clean  side  must  be  turned  up. 
This  may  be  done  every  hour  or  two.  The  idea 
is  to  keep  the  carpet  free  from  the  gangue,  or 
nearly  so,  as  nothing  catches  concentrates  better 
than  clean  Brussels  carpet,  With  very  little  ex- 
perience and  attention  this  will  do  the  work. 
An  apron  is  placed  at  the  lower  end  to  carry  off 
the  gangue. 

AMALGAMATION. 

The  first  and  most  important  point  is  to  thor- 
oughly understand  the  cleaning  of  the  mercury. 

First — Retorting  of  foul  mercury.  The  retort 
should  not  be  more  than  half  full,  and  covered 
with  a  layer  of  quick-lime  or  powdered  charcoal. 
Lute  and  wedge  the  cap  on  the  retort.  Cover 
the  pipe  with  wet  rags  and  allow  it  to  extend  to, 
but  not  in  the  water.  Keep  water  running  on 
the  rags,  and  commence  the  heating  very  gradu- 


56  PRACTICAL    MINING 

ally  and  slowly  until  the  retort  is  nearly  red. 
Stop  heating  before  it  is  fully  red  and  allow  it  to 
cool.  The  mercury  will  be  found  in  the  water. 

Second — To  clean  mercury  without  retorting: 
Put  the  mercury  in  a  fruit  jar  or  large  bottle,  say 
five  pounds.  To  this  add  one  teacup  full  of  nit- 
ric acid,  three  teacups  full  of  distilled  water. 
Allow  it  to  stand  for  twenty -four  hours,  shaking 
it  occasionally. 

HOW  TO  KEEP  MERCURY. 

It  should  be  kept  in  a  large  jar,  mug  or  bot- 
tle, preferably  a  bowl  or  large  mouthed  bottle. 
Put  into  the  bottle  5  pounds  of  mercury,  one 
pound  of  sal-ammoniac,  2  pounds  of  quick-lime, 
with  just  enough  water  to  dissolve.  Shake  it 
well.  Use  the  mercury  from  this  jar. 

DRESSING  THE  PLATES. 

Rinse  them  off  with  a  hose,  using  clean  water. 
If  they  are  fouled  or  dark,  go  over  them  with  a 
brush  or  flannel-mop,  washing  them  with  the 
following  solutions  as  may  be  best  suited  to  the 
conditions  which  will  be  given  below. 

The  best  for  general  purposes  is  solution 

No.  1. — Cyanide  of  potassium,     2  ozs. 
Caustic  soda,  5  ozs. 

Dissolved  in  five  gallons  of  water. 


PRACTICAL   ASSAYING  57 

When  the  plates  are  fouled  or  blackened  with 
black  sulphurets,  use  eithel  of  the  following: 

No,  2. — To  five  gallons  of  strong  brine  add 
one-half  pint  of  sulphuric  acid. 

No.  3. — Sal-ammoniac,  1  Ib. 

Lime,  3  Ibs. 

Carbonate  of  soda,  \  Ib. 

Go  over  the  plates  thoroughly  with  one  of 
these  solutions.  When  the  plates  are  fouled 
with  zinc,  black  oxide  of  manganese,  sulphate  of 
copper,  use 

No.  4. — Muriatic  acid,  1  Ib. 

Water,  5  gallons. 

After  having  cleaned  the  plates  and  used  one 
of  the  above  solutions,  take  from  the  bottle  one 
pound  of  mercury,  put  it  in  a  small  bottle  and 
add  one-half  ounce  of  sodium  amalgam. 

Stretch  a  piece  of  muslin  over  the  mouth  of 
the  bottle  and  sprinkle  the  plate  with  the  mer- 
cury; rub  them  smooth  with  a  flannel  mop  in 
clean  water.  They  are  then  ready  to  receive  the 
pulp  from  the  mill.  The  mercury  now  is  fed 
into  the  battery  every  half  hour.  The  quantity 
must  be  governed  by  the  amount  of  gold  in  the 
ore.  Two  and  one-half  ounces  of  mercury  is  suf- 
ficient to  amalgamate  and  hold  in  proper  condi- 
tion on  the  plates  one  ounce  of  gold.  The  mill- 
man  must  keep  the  plates  in  good  condition,  that 


PRACTICAL    MINING 

is,  the  mercury  should  be  kept  soft  on  the  plates 
but  not  to  run,  so  that  it  may  be  rubbed  up  with 
the  finger,  feeling  like  soft  putty,  and  as  the 
amalgam  accumulates,  it  should  be  kept  in  like 
condition,  but  must  be  spread  on  the  plates,  and 
not  be  allowed  to  remain  in  bunches  as  it  will. 
This  may  be  done  with  a  brush,  going  over  the 
plates  from  side  to  side,  the  brush  in  this  manner 
forming  very  fine  ridges.  When  the  ore  carries 
black  oxide  of  manganese  or  black  sulphurets 
the  plates  become  foul  so  often  that  it  is  a  very 
hard  matter  to  keep  them  clean,  and  the  follow- 
ing may  be  found  very  useful  not  only  in  keeping 
the  plates  clean  but  in  saving  the  fine  gold. 

Take  some  light  tent  cloth  or  heavy  cotton 
drilling;  cut  a  piece  six  feet  long  and  the  width 
of  the  plates;  tack  or  sew  a  narrow,  thin  lath 
across  each  end  and  in  the  middle  to  keep  the 
cloth  stretched  like  a  window  shade.  Place  this 
right  over  the  plates  thirty  inches  from  the  bat- 
tery and  just  below  the  first  copper,  raise  the 
upper  end  so  that  all  the  pulp  and  wrater  flow's 
under.  Allow  the  w^hole  piece  to  float  on  the 
pulp.  You  may  add  a  little  more  water  below 
the  battery.  This  arrangement  serves  to  force 
the  fine  gold  on  to  the  plate  and  at  the  same  time 
serves  to  force  the  foul  matter  off. 


PRACTICAL   ASSAYING  50 

Sometimes  the  water  prevents  amalgamation 
and  causes  the  loss  of  the  fine  gold,  even  when 
the  plates  seem  to  be  in  perfect  condition.  This 
is  often  the  case  when  the  water  is  used  from 
the  mipe  in  the  batteries.  When  this  is  the  case 
the  water  should  be  kept  in  a  tank,  adding  one 
bushel  of  lime  for  every  1 ,000  gallons  of  water. 

SODIUM  AMALGAM. —  This  is- prepared  by  dis- 
solving dry  chips  cut  from  clean  metallic  sodium 
in  dry  mercury.  Heat  it  very  gently  in  a  flask 
or  porcelain  dish;  add  the  chips  of  sodium  piece 
by  piece  until  the  mass  has  become  thick.  This 
must  always  be  kept  perfectly  dry  and  air  tight. 

CHLORINATION. 

On  page  60  see  apparatus  for  making  a  chlo- 
rine test,  which  can  be  purchased  for  $1.50. 

Place  in  the  bottom  of  the  funnel  "C"  some 
quartz  pulverized  pretty  fine,  a  layer  first  of  the 
coarser,  and  cover  with  the  fine  quartz.  This  is 
for  the  filter;  then  put  into  the  funnel  one  or  two 
ounces  of  the  concentrates  or  sulphurets  which 
must  be  roasted  to  destroy  the  sulphur,  to  be 
treated,  on  top  of  the  quartz;  then  place  the 
cover  (cut  out  of  a  pine  board)  over  the  whole 
and  lute  it  down  with  (Jough .  Now  mix  one 
ounce  of  black  oxide  of  manganese  and  one 
ounce  of  fine  salt,  and  put  it  into  the  generator, 


60 


PRACTICAL    MINING 


s 

w 

o 


PRACTICAL   ASSAYING  61 

"A;"  then  connect  the  generator,  as  shown.  To 
wash  bottle  or  any  clear  bottle  filled  with  water 
as  shown,  above  the  end  of  the  glass  tube,  con- 
nect this  bottle  wi'h  rubber  tube  to  the  bottom 
of  the  funnel  as  shown.  No\\  pour  into  the 
small  funnel  top  of  glass  tube  in  the  generator, 
"A;"  water  to  cover  the  manganese  and  salt,  and 
then  add  2  ounces  of  sulphuric -acid,  a  little  at  a 
time,  and  in  a  minute  or  two  you  will  see  the 
chlorine  gas  begin  to  bubble  up  through  the 
water  in  the  bottle,  and  this  gas  will  pass 
through  the  rubber  tube  in  the  ore  in  the  funnel 
and  will  dissolve  the  gold.  If  there  is  a  leak 
you  will  detect  it  at  once  by  the  smell,  and  you 
can  readily  discover  it  by  dipping  a  stick  or  a 
sliver  into  ammonia  and  holding  it  all  around 
the  different  connections,  as  you  would  do  with 
a  lighted  match,  to  discover  a  gas.  The  moment 
the  stick  wet  with  ammonia  is  touched  with  the 
gas,  a  whitish  fume  will  rise  from  the  stick. 
The  leak  when  found  can  be  checked  at  once 
with  dough.  When  the  bubbles  cease  in  the 
bottle,  add  a  little  more  acid;  let  it  work  for  six 
or  eight  hours,  then  take  the  cover  from  the  ore, 
and  remove  the  rubber  tube  from  the  bottom  of 
the  funnel  and  place  a  bowl  under  the  funnel 
and  begin  to  pour  hot  water  on  the  ore,  which 
will  leach  down  through  the  ore  and  carry  the 


0)2  PRACTICAL    MINING 

chloride  of  gold  with  it  in  solution,  after  it  has 
been  thoroughly  leached  out.  You  precipitate 
the  gold  from  the  solution  with  sulphate  of  iron 
and  a  few  drops  of  muriatic  acid,  which  you  can 
make  by  dissolving  any  hoop  iron  or  thin  sheets 
of  iron  in  sulphuric  acid.  The  whole  is  filtered 
and  the  brown  precipitate  is  then  dried  and 
mixed  with  litharge  and  borax,  and  melted. 
The  lead  button  is  then  cupelled  as  in  an  assay. 
The  better  way  is  to  thoroughly  rinse  the  ore 
with  hot  water,  to  leach  out  all  the  gold,  and 
assay  for  the  pulp  to  determine  the  per  cent,  of 
gold  extracted. 

TO  MEASURE  INACCESIBLE  DISTANCES. 
A  very  simple  and  convenient  method  of  meas- 
uring inaccessible  distances,  as  across  a  canyon 
or  river  is  shown  on  page  63.  Suppose  it  is  de- 
sired to  know  the  distance  from  a  given  point  as 
"A"  across  a  stream  to  "E"  (see  cut.)  Step  off  or 
measure  with  a  line,  100  feet,  yards,  or  rods,  at 
right  angles  from  the  starting  point  "A"  to  "B," 
and  set  a  stake  on  the  same  line  at  80,  one-fifth 
of  the  100  at  "D."  Now  measure  or  step  off  at 
right  angles  from  ' '  B"  to  a  point  "C, "  where  a  line 
to  '  4E"  will  cut  the  stake  at  "D"  as  shown  by  the 
dotted  line  from  "C"  to  "E."  Now  the  distance 
from  "B"  to  "C"  multiplied  by  four  gives  the 
correct  distance  from  "A"  to  "E." 


PRACTICAL   ASSAYING 


^ 


64 


PRACTICAL   MINING 


o 


PRACTICAL   ASSAYING  65 

LEVELING  INSTRUMENT. 

There  are  very  many  times  and  places  where 
it  is  necessary  to  know  the  depth  of  shaft  to  tap 
a  drift  or  the  length  of  a  tunnel  to  cut  a  shaft, 
and  it  is  very  seldom  convenient  to  have  a  sur- 
veyor or  even  a  compass.  On  page  64  I  have 
shown  a  cut  of  an  instrument  I  have  made  and 
u.3ed,  that  is  very  simple,  satisfactory,  and  easily 
made.  Take  two  pieces  of  hard,  sound,  clear 
board,  \  inch  thick,  1  inch  wide  and  two  feet 
long,  dressed,  and  rule  them  the  same  as  an  or- 
dinary two  foot  rule.  Fasten  them  together  at 
one  end  with  a  common  wood  screw;  now  cut  a 
quadrant,  and  \  inch  or  more  out  of  a  piece  of 
thin  brass  or  tin  and  mark  the  degrees  on  it  from 
0  to  90,  as  shown  at  k<C;"  the  \  inch  is  to  fasten 
to  the  base  "A;"  let  "0"  begin  at  the  top  edge 
of  "A."  Let  this  in  flush  with  the  face  of  the 
piece  "A"  and  fasten  with  small  screws;  now 
take  a  piece  of  glass  tubing,  cork  one  end  and 
fill  it  with  alcohol;  cork  and  seal  both  ends; 
countersink  a  place  in  the  middle  of  base  "A" 
and  fasten  this  in  it  as  shown  at  "D."  This 
makes  a  good  spirit  level  of  the  base.  Stick  a 
piece  of  a  pin  in  each  end  of  the  leg  "B,"  for 
sights;  now  the  instrument  is  ready  for  use.  For 
grading  a  ditch  or  flume,  or  tunnel,  push  the  leg 
"B"  below  the  base,  the  number  of  inches  re- 


66  PRACTICAL    MINING 

quired  for  the  grade,  if  end  of  the  leg  "B"  is 
pushed,  below  the  end  of  the  level  —  2  inches. 
This  would  make  the  grade  one  inch  to  the  foot, 
etc.,  holding  the  base  level;  the  leg  "B"  forms 
the  pitch,  or  incline,  or  base  required. 

For  measuring  distances,  running  tunnels, 
etc.,  when  it  is  desired  to  know  the  length  of  a 
tunnel  to  cut  a  lode  or  shaft:  Let  "A,"  fie.  1, 


FIGURE  1. 


be  the  top  of  the  lode  or  shaft,  and  "C"  be  the 
point  where  the  tunnel  is  to  start.  Now  place 
the  instrument  level  at  "C;"  let  the  leg  "B" 
point  to  "A,"  and  note  the  angle,  and  then 
measure  the  distance  carefully  up  to  the  shaft  at 
"A,"  and  take  the  pitch,  or  angle,  of  the  incline 
or  pitch  of  the  shaft.  Now  from  the  table  of 
sines,  get  the  sine  of  the  angle  at  "c"  and  the 
sine  of  the  angle  at  "a;"  then  the 

Length  of  tunnel  "B  -  C"— "AC"Xsme"'a". 

Depth  of  shaft       "A  -  B"="AC"Xsine  "c". 


PRACTICAL   ASSAYING 
C 


67 


FIGURE  2. 


Suppose  it  is  desired  to  get  the  distance  to  a 
certain  point,  with  the  instrument,  accurately,  set 
a  stake  at  the  starting  point,  "A;"  then  measure 
off  any  distance  at  right  angles  from  the  line 
"AC"  to  point  "B,"  set  the  base  or  level  at  "B" 
and  sight  back  to  "A;"  then  point  the  leg  of  the 
instrument  to  "C"  and  note  the  angle,  which  in 
this  example,  figure  2,  is  60°,  then  the  angle  at 
"C"  must  be  30°  and  the  distance  from  "A"  to 
'  1B"  is  80  (feet,  yards  or  rods).  The  distance  from 


Example:  Angle 
(See  table  of  sines.) 
5000.  Now  the  line 
-*-  5000  —  138.56. 


. 

sine  "c" 

at  "B"  is   60°,  sine   8660. 

Angle  at  "C"  is  30°,  sine 

"AB"  is  80  X  8660  =  6928 


68  PRACTICAL    MINING 


SUNDRY  ITEMS. 

DIFFERENT  GRADES  OF  GOLD. 

Twenty-four-carat  gold  is  all  gold;  22-carat 
gold  has  22  parts  of  gold,  one  of  silver  and  one 
of  copper;  18-carat  gold  has  18  parts  of  gold  and 
three  each  of  silver  and  copper;  12-carat  gold  is 
half  gold  and  has  3^  parts  of  silver  and  83  of 
copper.  Its  specific  gravity  is  about  15;  pure 
gold  is  19. 

LOCATION  NOTICE. 

There  are  many  forms;  the  shortest  and  most 
concise  is  as  good  as  any,  besides  being  the  eas- 
iest. Take  a  soft  pine  board  and  a  hard  lead 
pencil,  and  the  writing  will  sometimes  outlast 
your  claim.  I  have  written  notices  that  have 
remained  legible  for  six  years. 

"Notice  is  hereby  given  that  I,  Samuel  Bur- 
bank,  claim  by  right  of  discovery  and  to  locate 
under  the  mining  laws  of  the  state  of  California, 
1,500  feet  in  length  and  600  feet  in  width  along 
this  vein  or  lode  to  be  known  as  the  ''Gold  Bug" 
beginning  at  center  of  this  shaft  (cut  or  mound) 


PRACTICAL   ASSAYING  69 

and  running  700  feet  in  a  northerly  direction  and 
800  feet  in  a  southerly   direction,  together  with 
300  feet  on  either  side  of  this  vein  or  lode. 
Located  January  1,  1897. 

SAMUEL  BURBANK,  Locator." 

Now  have  a  copy  of  this  recorded. 

MINER'S  INCH. 

An  outlet  of  two  inches  width,  four  inches  of 
water  above  the  outlet,  one  inch  wide,  is  two 
miner's  inches,  and  a  flume  ten  inches  with  six 
inches  of  water,  would  give  twenty  miner's 
inches. 

SOLUTION  NO.  3  FOR  WORKING  BLACK 
SAND. 

Dissolve  one  pound  of  cyanide  potassium  and 
two  pounds  of  caustic  soda  in  40  gallons  of 
water.  Use  one  gallon  of  this  solution  mixed 
with  six  gallons  of  water.  This  will  free  the 
gold  so  that  it  will  amalgate  when  it  comes  in 
contact  with  the  mercury. 

209  feet  square  is  one  acre. 

A  gallon  of  fresh  water  weighs  84  pounds,  and 
contains  231  cubic  inches. 


70  PRACTICAL    MINING 

A  cubic  foot  of  water  weighs  62^  pounds,  and 
contains  1,728  cubic  inches  or  7-J  gallons.  A 
cubic  inch  of  water  weighs  .0361  pounds. 

The  friction  of  water  in  pipes  increases  as  the 
square  of  its  velocity. 

The  capacity  of  pipes  increases  as  the  square 
of  the  diameters,  thus  doubling  the  diameter 
increases  the  capacity  four  times. 

To  find  the  area  of  a  piston,  square  the  diame- 
eter  and  multiply  by  .7854. 

In  calculating  horse  power  of  tubular  boilers, 
15  square  feet  of  heating  surface  is  equivalent  to 
one  nominal  horse  power. 

Each  nominal  horse  power  of  boilers  will  re- 
quire about  one  cubic  foot  of  water  per  hour. 

The  mean  pressure  of  the  atmosphere  is  usu- 
ally estimated  at  14.7  pounds  per  square  inch,  so 
that,  with  a  perfect  vacuum,  it  will  sustain  a 
column  of  mercury  29.9  inches,  or  a  column  of 
water  33.9  feet  high. 

To  find  the  capacity  of  a  cylinder  in  gallons: 
Multiplying  the  area  in  inches  by  the  stroke  in 
inches  will  give  the  total  number  of  cubic  inches: 
divide  this  amount  by  231  (which  is  the  cubical 
contents  of  a  gallon  in  inches),  and  the  product 
is  the  capacity  in  gallons. 


PRACTICAL   ASSAYING  71 

To  find  the  pressure  in  pounds  per  square 
inch  of  a  column  of  water,  multiply  the  height 
of  the  column  in  feet  by  .484.  Approximately 
each  foot  elevation  is  called  equal  to  one-half 
pound  pressure  per  square  inch. 

To  find  the  diameter  of  a  pump  cylinder  to 
move  a  given  quantity  of  water  per  minute  at  a 
piston  travel  of  100  feet  per  minute,  divide  the 
number  of  gallons  by  4,  then  extract  the  square 
root,  and  the  product  will  be  the  diameter  of  the 
pump  cylinder  in  inches. 

To  find  the  horse  power  required  to  elevate 
water  to  a  given  height,  multiply  the  amount  of 
water,  in  gallons,  to  be  raised  per  minute  by 
8.35,  the  weight  of  a  gallon  of  water,  and  this 
product  by  the  height  (in  feet)  of  the  discharge 
from  the  point  of  suction;  divide  the  result  by 
33,000,  and  you  have  the  theoretical  horsepower 
required  to  raise  the  amount  of  water  a  certain 
distance.  Owing  to  the  friction  of  water  in 
pipes,  the  friction  of  machinery  and  the  pump 
itself,  a  liberal  allowance  must  be  made  for  fric- 
tion . 

The  area  of  the  steam  piston,  multiplied  by 
the  steam  pressure,  give  the  total  amount  of 
pressure  exerted.  The  area  of  the  water  piston, 
multiplied  by  the  pressure  of  water  per  square 


72  PRACTICAL   MINING 

inch,  gives  the  resistance.  A  margin  of  from  30 
to  50  per  cent,  must  be  added  to  move  the  piston 
at  the  required  speed. 

To  find  the  velocity  in  feet  per  minute  neces- 
sary to  discharge  a  given  body  of  water  in  a 
given  time,  multiply  the  number  of  cubic  feet  of 
water  by  144,  and  divide  the  product  by  the  area 
of  the  pipe  in  square  inches. 

Amount  of  water  to  mill  one  ton  of  ore  is  from 
1,200  to  2,400  gallons,  the  average  being  about 
1,800  gallon  to  the  ton  of  ore. 

Small  particles  of  anything  may  be  picked  up 
with  the  moistened  point  of  a  pin  or  needle. 


PRACTICAL    ASSAYING 


73 


ASSAY  TABLE 

Showing  the  amount  of  Gold  and  Silver,  in  ounces  and  frac- 
tions, contained  in  one  ton  of  ore,  of  two  thousand  pounds,  from  the 
weight  of  fine  metal  obtained  in  an  assay  of  (half  an  ounce)  two 
hundred  and  forty  grains  of  ore. 


S^t  8,8,81 
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.001                            1.21 

$    1.56 

$    25.01 

2 

2.43 

3.14 

50.23 

3 

3.64 

4.71 

75.24 

4 

4.86                             6.28 

100.46      j 

5 

6.08 

7.86 

125.68 

7.29 

9.42 

150.70 

7 

8.51 

10.99 

175.92 

8 

9.72 

12.57 

200.93 

9 

10.94 

14.14 

226.15 

.010 

12.15 

15.69 

251.16 

1 

13.37 

17.29 

276.38 

2 

14.58 

18.85 

301.29 

3 

15.80 

20.43 

328.61 

4 

17.01 

21.99 

351  63 

5 

18.23 

23.57 

376.  85 

6 

19.44 

25.13 

401.86 

7 

20.66 

26.71                        427.08 

8 

21.87 

28.27 

452.09 

9 

23.09 

29.85 

477.31 

.020 

24.30 

31.42 

502.32 

1 

25.51 

32.99 

527.54 

2 

26.74 

34.57 

532.76 

3 

27.95 

36.14 

577.78 

4 

29.17 

37.71 

603.00 

5 

30.38 

39.28 

628.01 

6 

31.60 

40.86 

653.23 

7 

32.81 

42.42 

678.24 

8 

34.03 

44.00 

703.43 

9 

35.24 

45.56 

728.47      1 

.030 

36.46 

47.14 

753.69 

1 

37.67 

48.70 

778.71 

2 

38.89 

50.28 

803.93 

3 

40.10 

51.85 

838.94 

4 

41.32 

53.42 

854.16 

5 

42.53 

54.99 

879.17 

6 

43.75 

56.56 

904.89 

7 

44.96 

58.13 

929.40 

8 

46.18 

59.71 

954.62 

9 

47.39 

61.27 

979.64 

PRACTICAL   MINING 


ASSAY  TABLE  —  Continued. 

Showing  the  amount  of  Gold  and  Silver,  in  ounces  and  frac- 
tions, contained  in  one  ton  of  ore.  of  two  thousand  pounds,  from  the 
weight  of  fine  metal  obtained  in  an  assay  of  (half  an  ounce)  two 
hundred  and  forty  grains  of  ore. 


S2.I  S,S,=i 

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£"  5- 

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q  3 

!fi 

.040 

48.61 

$  62.85 

$  1004.86 

1 

49.83 

64.43 

1030.07 

2 

51.04 

65.99 

1055.09 

3 

52.26 

67.57 

1080.31 

4 

53.47 

69.13 

1105.32 

5 

54.69 

70.71 

1130.54 

6 

55.90 

72.27 

1155  .  55 

7 

57.12 

73.85 

1180.77 

8 

58.33 

75.42 

1205.79 

9 

59.55 

76.99 

1231.00 

.050 

60.76 

78.56 

1256.02 

1 

61.98 

80.13 

1281.24 

2 

63.19 

81.70 

1306.25 

3 

64.41 

83.28 

1331.47 

4 

65.62 

84.84 

1356.48 

5 

66.84 

86.42 

1381.70 

6 

68.05 

87.98 

1406.72 

7 

69.27 

89.56 

1431.93 

8 

70.48 

91.12 

1456.95 

9 

71.70 

92.70 

1482.17 

.060 

72.92 

94.28 

1507.39 

1 

74.13 

95.84 

1532.40 

2 

75.35 

97.42 

1557.62 

3 

.     76.56 

98.99 

1582.63 

4 

77.78 

100.56 

1607.85 

5" 

78.99 

102.13 

1632.86 

6 

80.21 

103.70 

1658.08 

7 

81.42 

105.27 

1683.10 

8 

82.64 

106.85 

1708.32 

9 

83.85 

108.41 

1733.33 

.070 

85.07 

109.99 

1758.55 

1 

86.28 

111.55 

1783.56 

2 

87.50 

113.13 

1808.78 

3 

88.71 

114.69 

1833.79 

4 

89.93 

116.27 

1859.01 

5 

91.14 

117.84 

1884.03 

6 

92.36 

119.41 

1909.25 

7 

93.58 

120.99 

1934.47 

8 

94.79 

122.56 

1959.48 

9 

96.01 

124.13 

1984.70 

PRACTICAL   ASSAYING 


75 


ASSAY  TABLE  —  Continued. 

Showing  the  amount  of  Gold  and  Silver,  in  ounces  and  frac- 
tions, contained  in  one  ton  of  ore.  of  two  thousand  pounds,  from  the 
weight  of  fine  metal  obtained  in  an  assay  of  (half  an  ounce)  two 
hundred  and  forty  grains  of  ore. 


If  240  grains 
of  Ore  give 
of  Fine  Metal 
—  Thousand: 
iof  the  unit  ot 
J10  grains. 

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.080                          97.22 

$  125.70 

$  2009.71 

1 

98.44 

127.27 

2034.93 

2 

99.65 

128.84 

2059.94 

3 

100.87 

330.42 

2085.16 

4 

102.08 

131.98 

2110.18 

5 

103.30 

133.56 

2135.40 

6 

104.51 

135.12 

2160.41 

7 

105.73 

136.70 

2185.63 

8 

106.94 

138.26 

2210.64 

9 

108.16 

139.84 

2235.86 

.090 

109.37 

141.41 

2260.87 

1 

110.59 

142.98 

2286.09 

2 

111.80 

144.55 

2311.11 

3 

113.02 

146.13 

2336.33 

4 

114.23 

147.69 

2361.34 

5 

115.45 

149.27 

2386.56 

6 

116.67 

150.84 

2411.78 

7 

117.88 

152.41 

2436.79 

8 

119.10 

153.99 

2462.01 

9 

120.31 

155.55 

2487.02 

.100 

121.53 

157.13 

2512.24 

.200 

243.05 

314.26 

5024.48 

.300 

364.58 

471.39 

7536.72 

.400 

486.11 

628.52 

10048.96 

.500 

607.64 

785.65 

12561.21 

.600 

729.16 

942.78 

15073.45 

.700 

850.69 

1099.91 

17585.70 

.800 

972.22 

1257.04 

20097.93 

.900 

1093.75 

1414.17 

22610.17 

1.000 

1215  27 

1571.30 

25121.41 

PRACTICAL    MINING 


ASSAY  TABLE 

Showing  the  amount  of  Gold  and  Silver,  in  ounces  and  fractions, 
contained  in  one  ton  of  ore,  of  two  thousand  pounds,  from  the 
weight  of  fine  metal  obtained  in  an  assay  of  20  Grammes  of  ore. 


If  20  grams 
of  Ore  give 
of  Fine  Metal 
-  Thousands 
of  the  unit  of 
|l  Gram. 

I2,oo 

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:  £rc 

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.001 

1.458 

|    1.88  5 

$    30.14  6 

2 

2.916 

3  77.1 

60  29.2 

8 

4.374 

5.65.7 

90.43.8 

4 

5  833 

7.54  2 

120  58.5 

5 

7.291 

9.42.8 

150.73.1 

g 

8  749 

11.31  3 

180.87.7 

7 

10.208 

13.19  8 

211.02.4 

8 

11.666 

15.08.4 

241.17  0 

9 

13.124 

16.95.9 

27131.6 

.010 

14.583 

18.85.4 

301.46.3 

1 

16.041 

20.73.9 

331  60.9 

2 

17.499 

22.62.5 

361.75.5 

3 

18.958 

24.51.0 

391.90.1 

4 

20.416 

26.39.5 

422.04.8 

5 

21.874 

28.28.1 

452.19.4 

6 

23.333 

30.16.6 

482.34.0 

7 

24.791 

32.05.2 

512.48.7 

8 

26.249 

33.93  7 

542.63.3 

9 

27  708 

35.82.4 

572.77.9 

.020 

29.166 

37.70.8 

602.92.6 

1 

30.624 

39.59.4 

633.07  2 

2 

32  083 

41.47.9 

663.21.8 

3 

33  541 

43.36.4 

693.36.5 

4 

34.999 

45  25  0 

723.51.1 

5 

36.458 

47.13.5 

753.65.7 

6 

37.916 

49.02.1 

783.80.3 

7 

39.374 

50.90.6 

813  95.0 

8- 

40.833 

'  52  79.2 

844.09.6 

9 

42.291 

54  67.7 

874.24.2 

.030 

43.749 

56  56.2 

904.38.9 

1 

45.208 

58.44.8 

934.53.5 

2 

46.636 

60.33.3 

964  68.1 

3 

48.124 

62.21.9 

994.82  8 

4 

49.583 

64.10.4 

1024.97.4 

5 

51  041 

65.99.0 

W55.12.0 

6 

52.499 

67.87.5 

1085  26.7 

7 

53.958 

69.76.0 

1115.41  3 

8 

55.416 

71.64.6 

1145.55.9 

9 

56.874 

73.53.1 

1175.70.5 

.040 

58.333 

75.41.9 

1205.85.0 

1 

59.791 

77.30.4 

1235.99.8 

2 

61.249 

79.18.9 

1260.11.  4 

3 

62.708 

81.07.5 

1296.29.1 

PRACTICAL    ASSAYING 


77 


ASSAY  TABLE  —  Continued. 

Showing  the  amount  of  Gold  and  Silver,  in  ounces  and  fractions, 
contained  in  one  ton  of  ore,  of  two  thousand  pounds,  from  the 
weight  of  fine  metal  obtained  in  an  assay  of  20  Grammes  of  ore. 


£8,1  8,3,5 

im^ 

•$$inv 
rfj&i 
sjMl 

I  °  99 

sail 

m 

\  HA 

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Q£  f 

SI 

iff 

.044 

64.166 

$  82.96.0 

$  1326.43.7 

5 

65.624 

84.84.6 

1356.58.3 

6 

67.0&3 

86.73.1 

1386.73.0 

7 

68.541 

88.61.7 

1410.87.6 

8 

69.999 

90.50.2 

1447.02.2 

9 

71.458 

92.38.7 

1477.16.8 

.050 

72.916 

94.27.3 

1507.81.5 

1 

74.374 

96.15.9 

1537.46.1 

2 

75.833 

98.04.4 

1567.60.7 

3 

77.291 

99.93.0 

1597  75.4 

4 

78.749 

101.81.5 

1627.90.0 

5 

80.208 

103.70.1 

1658.04.6 

6 

81.666 

105.58.6 

1688.19.3 

7 

83.124 

107.47.1 

1718.33.9 

8 

84.583 

109.35.7 

1748.48.5 

9 

86.041 

111.24.2 

1778.63.2 

.060 

87.499 

113.12.8 

1808.77.8 

1 

88.958 

115.01.3 

1838.92.4 

2 

90.416 

116.89.9 

1869.07.0 

3 

91.874 

118.78.4 

1899.21.7 

4 

93  333 

120.67.0 

1929.36.3 

5 

94.791 

122.55.5 

1959.50.9 

6 

96.249 

124.44.0 

1989.65.6 

7 

97.708 

126.32.6 

2019.80.2 

8 

99.166 

128.21.1 

2049.94.8 

9 

100.644 

130.09.7 

2080.09.5 

.070 

102.083 

131.98.3 

2110.24.1 

1 

103.541 

133.86.8 

2140.38.7 

2 

104.999 

135.75.4 

2170.53.4 

3 

106.458 

137.63.4 

2200.68.0 

4 

107.916 

139.52.4 

22C0.82.6 

5 

109.374 

141.41.0 

2260.97.2 

6 

110.833 

143.29.5 

2291.11.9 

7 

112.291 

145.18.1 

2821.25.5 

8 

113.749 

147.05.6 

2351.41.1 

9 

115.208 

148.95.2 

2381.55.8 

.080 

116.666 

150.83.7 

2411.70.4 

1 

118.124 

152.72.2 

2441.85  0 

2 

119.583 

154  60.7 

2471  99  7 

3 

121.041 

156  49.4 

2502.14.3 

4 

122.499 

158.37  9 

2532.28  9 

5 

123  957 

160.26  5 

2562.43.6 

6 

125.416 

162.15.0 

2592.58.2 

78 


PRACTICAL   MINING 


ASSAY  TABLE  —  Continued. 

Showing  the  amount  of  Gold  and  Silver,  in  ounces  and  fractions 
contained  in  one  ton  of  ore.  of  two  thousand  pounds,  from  the 
weight  of  fine  metal  obtained  in  an  assay  of  20  Grammes  of  ore. 


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126.874     ! 

$  164.03.5 

$  2622.72.8 

8 

128.332 

165  92.5 

2652.87  4 

9 

129  791 

167.80.6 

2683  02.1 

.090 

131  2-M) 

169.69  2 

2713.10.7 

1 

132.708 

171.57.7 

2743.31.3 

2 

134  166 

173.46.3 

2773  46  0 

3 

135.  G24 

175.34.8 

2803.60.6 

4 

137.083 

177.23.3 

2833.75.2 

6 

13S.541 

179.11.9 

2863  89.9 

6 

139.999 

181.00.4 

2894.04  5 

7 

141  4,\S 

182  89.0 

2924  191 

8 

142.  OK; 

184.77.5 

2954.  33.  7 

9 

144.374 

186.66.1 

2984.  '48  4 

.100 

14r).833 

188  54.7 

8014.68.0 

.200 

291.666 

377.09 

6029.26 

.300 

437.499 

565.64 

9043  91 

.400 

583  333 

754.19 

12058.55 

.500 

729.166 

942.73 

15073  18 

.600 

874.999 

1131.29 

18087.82 

.700 

1020.833 

1319.83 

21102.46 

.800 

1166.666 

1508.38 

24117  09 

.900 

1312.499 

1696.93 

271C1  73- 

l.OOOJ 
Orl  Gram  I 

1458  333 

1885  47 

30146.37 

2      .. 

2916.666 

3770.95 

60292.74 

3      . 

4374.999 

5656.42 

90439.10 

4      . 

5833.333 

7541.90 

120585.47 

5      . 

7291.666 

9427.37 

150731.84 

6      . 

8749.999 

11312.85 

180878.21 

7 

10208.333 

13198.32 

211024.58 

8      . 

11666.666 

15083.80 

241170.94 

9 

13124.999 

16964.27 

271317.31 

10      . 

14583.333 

18854.75 

301433  68 

11      . 

16041.664 

20740.22 

331610.05 

12 

17499  999 

22625.70 

361756.42 

13      . 

18958.333 

24511  17 

391902.78 

14 

20416.666 

263%.  65 

422049.15 

15      . 

21874.999 

28282.12 

452195.52 

16      . 

23333.333 

30167.60 

482341.89 

17 

24791.666 

32053.07 

512488.25 

18      . 

26249.999 

33938.55 

542604.62 

19 

27708.333 

35824.02 

572780.99 

20      . 

29166.666 

37709.50 

602927.36 

PRACTICAL   ASSAYING  79 

The  foregoing  table  is  computed  from  an  assay 
of  20  grammes,  which  is  a  convenient  amount 
for  a  crucible  assay.  When  a  scorification  assay 
is  made,  two  scorifiers  are  used  with  10  grammes 
in  each,  and  the  two  buttons  (which  should 
weigh  exactly  alike,  if  the  assay  is  correct)  are 
weighed  together  and  treated  as  one  assay.  It  is 
then  only  necessary  to  compare  the  tables  with 
the  number  of  milligrammes  obtained,  in  the 
first  column;  in  the  next  will  be  found  the  num- 
ber of  ounces  to  the  ton,  and  the  value  of  gold 
and  silver  in  the  other  columns.  A  single  exam- 
ple will  fully  illustrate  it. 

-0  grammes  of  ore  yi^ld  a  metallic  button  of 
gold  and  silver  weighing  830  milligrammes. 

Boiled  in  nitric  acid. — Gold  weighing  32  milli- 
grammes remains. 

380—32  gold— 348  silver. 

In  the  first  column  find  32  milligrammes  and 
you  have  46.666  ozs.  Troy  and  its  value  in  gold 
column,  $964.68.  In  the  first  column  find  348 
milligrammes.  To  do  this  you  must  add  48  and 
300,  and  you  have  69.999+437.499—507.49  ozs. 
Troy,  and  its  value  in  silver  column  90.50+ 
565.54— $656.14.  The  result  will  be, 

Gold         46.666      ozs.  Troy —$964.68. 

Silver     507.49         "       "      —  656.14. 

Value  per  ton  of  2,000  Ibs $1,620.82. 


80 


PRACTICAL    MINING 


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Length. 


* 

3  S3 


« 

3  N5«, 

n  f-4  r* 

Ift 


|  Thick's 

of 

|    Metal. 
^Weight 

per 

Length . 
Thick's 

oi 
Metal. 


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?! 
!| 

O 

9 

? 

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n 


>  C"  CO 
.  tC  O» 


Weight 

per 
Length. 


Thick's 

of 
Metal. 


Weight 

per 
Length. 


Thick's 

of 
Metal. 

Weight 

per 
Length. 

Thick's 

of 
Metal. 


Weight 

per 
Length. 


X3  ^  o 

a^p 

?        PH 


O   CO 


Contents  in 

galons  for  1  ft. 

in  Length. 


I 


w    O 
• 


84 


PRACTICAL    MINING 


TABLK  OF  NATURAL  SINES. 


De-     (), 

gree.  j    U 

10'    20' 

30' 

40' 

50' 

0     .0000 

.00129     .0058 

.  U087 

.0116 

.0145 

1 

.0175 

.U2U4 

.0233     .i)2li2 

.0291 

.0320 

2 

.03-19 

.0378 

.0407     .0436 

.0465 

.0494 

3 

.05:23 

.0552 

.0581  1   .1.010 

.0640 

.0669 

4 

.0698 

.0727 

.0756  !   .0785 

.0814 

.0843 

5 

.0872 

.0901 

.0929 

.0958 

.0987 

.1016 

6 

.10-15 

.1074 

.1103 

.1132 

.1161 

.1190 

7 

.1219 

.1.248 

.1270 

.1305 

.1334 

.1363 

8 

.1392 

.1421     .1-149 

.1478 

.1507 

.1536 

9 

.1564 

.1593 

.1622 

.1C>50 

.1679 

.1708 

10 

.1736 

.1765 

.1794 

.1822 

.1851 

.1880 

11 

.1908 

.19:i7 

.1965 

.11)<J4 

.2022 

.2051 

12 

.2079 

.2108  !   .2136 

.2164 

.2193 

.2221 

13 

.2250 

.2278 

.2:;06 

.2884 

.2363 

.2391 

14 

.2419 

.2447 

.2476 

.2504 

.2532 

.2560 

15 

.2588 

.2616 

.2644 

.2672 

.2700 

.2728 

16 

.2756 

.2784 

.2812 

.2840 

.2868 

.2896 

17 

.2924 

.2952 

.2979 

.8007 

.3035 

.3062 

18 

.30CO 

.3118 

.3145 

.3173 

.3201 

.3228 

19 

.3256 

.3283 

.3311 

.3338 

.3365 

.3393 

20 

.3420 

.3448 

.3475 

.3502 

.3529 

.3557 

21 

.3584 

.3611 

.3638 

[3665 

.3692 

.3719 

22 

.3746 

.3773 

.3800 

.3827 

.3854 

.3881 

23 

.3907 

.3934 

.3961 

.3987 

.4014 

.4041 

24 

.4067 

.4094 

.4120 

.4147 

.4173 

.4200 

25 

.4226 

.4253 

.4279 

.4:.05 

.4331 

.4358 

26 

.4384 

.4410 

.4436 

.4462 

.4488 

.4514 

27 

.4540 

.4566 

.4592 

.4617 

.4643 

.4669 

28 

.4695 

.4720 

.4740 

.4772 

.4797 

.4823 

29 

.4848 

.4874 

.4899 

.4924 

.4950 

.4975 

30 

.5000 

.5025 

.5050 

.6075 

.5100 

.5125 

31 

.51™ 

.5175 

.5200 

5225 

.5250 

.5275 

32 

.oiC9 

.5324 

.5348 

.5373 

.5398 

.5422 

33 

.54-16 

.5471 

.5495 

.5519 

.5544 

.5568 

34 

.5592 

.5616 

.5640 

.5664 

.5688 

.5712 

35 

.5736 

.5760 

.5783 

.5807 

.5831 

.5854 

36 

.5878 

.5901 

.5925 

.5948 

.5972 

.5995 

37 

.6018 

.6041 

.6065 

.6088 

.61H 

.6134 

38 

6157 

.6180 

.6202 

.6225 

.6248 

.6271 

39 

.6293 

.6316 

.6338 

.6361 

.6383 

.6406 

40 

.6428 

.6450 

.6472 

.6494 

.6517 

.6539 

41 

.65G1 

.6583 

.6604 

.6626. 

.6648 

.6670 

42 

.66C1 

.6713 

.6734 

.6756 

.6777 

.6799 

43 

.6820 

.6841 

.6862 

.6884 

.6905 

.6926 

44 

.6947 

.6967 

.6988     .7009     .7030  |   .7050 

PRACTICAL   ASSAYING 


85 


TABLE  OF  NATURAL  SINES. 


De- 
gree. 

0' 

10' 

20' 

30' 

40' 

50' 

45 

.7071 

.7092 

.7112 

.7133 

.7153 

.7173 

45 

.7193 

.72M 

.7234 

.7254 

.7274 

.7294 

47 

.7314 

.7333 

.7353 

.7373 

.7392 

.7412 

48 

.7431 

.7451 

.7470 

.7490 

.7509 

.7528 

49 

.7547 

.7566 

.7585 

.7604 

.7623 

.7642 

50 

.7630 

.7679 

.7698 

.7716 

.7735 

.7753 

51 

.7771 

.7790 

.7808 

.7826 

.7844 

.7832 

52 

.7880 

.7898 

.7916 

.7934 

.7951 

.7969 

53 

.7986 

.8004 

.8021 

.8039 

.8056 

.8073 

54 

.8090 

.8107 

.8124 

.8141 

.8158 

.8175 

55 

.8192 

.8208 

.8225 

.8241 

.  .8258 

.8274 

56 

.8290 

.8307 

.8323 

.8339 

.8355 

.8371 

57 

.8387 

.8403 

.8418 

.8434 

.8450 

.8465 

58 

.8480 

.8496 

.8511 

.8526 

.8542 

.8557 

59 

.8572 

.8587 

.8301 

.8616 

.8631 

.8646 

60 

.8360 

.8375 

.8389 

.8704 

.8718 

.8732 

61 

.8746 

.8760 

.8774 

.8788 

.8802 

.8816 

62 

.8829 

.8343 

.8857 

.8870 

.8884 

.8897 

63 

.8310 

.8323 

.8936 

.8949 

.8962 

.8975 

64 

.8988 

.9001 

.9013 

.9026 

.9038 

.9051 

65 

.9033 

.9075 

.9088 

.9100 

.9112 

.9124 

66 

.9135 

.9147 

.9159. 

.9171 

.9182 

.9194 

67 

.9205 

.9216 

.  .9228 

.9239 

.9250 

.9262 

68 

.9272 

.9283 

.9293 

.9304 

.9315 

.9325 

69 

.9336 

.9346 

.9356 

.9367 

.9377 

.9387 

70 

.9397 

.9407 

.9417 

.9426 

.9436 

.9446 

71 

.9455 

.9435 

.9474 

.9433 

.9492 

.9502 

72 

.9511 

.9520 

.9528 

.9537 

.9546 

.9555 

73 

.9533 

.9572 

.9580 

.9588 

.9596 

.9605 

74 

.9513 

.9321 

.9328 

.9336 

.9344 

.9652 

75 

.9359 

.9357 

.9374 

.9331 

.9689 

.9696 

76 

.9703 

.9710 

.9717 

.9724 

.9730 

.9737 

77 

.9744 

.9750 

.9757 

.9763 

.9769 

.9775 

78 

.9781 

.9787 

.9793 

.9799 

.9805 

.9811 

79 

.9316 

.9322 

.9827 

9333 

9838 

.9843 

80 

.9343 

.9353 

.9858 

.9853 

.9368 

.9372 

81 

.9377 

.9331 

.9386 

.9390 

.9894 

.9899 

82 

9903 

.9307 

.9311 

9314 

.9318 

.9922 

83 

.9925 

.9329 

.9332  - 

.9936 

.9939 

.9942 

84 

.9945 

.9918 

.9351 

.9954 

.9957 

.9959 

85 

.9332 

.9364 

.9367 

.9969 

.9971 

.9974 

86 

.9976 

.9378 

.9380 

.9931 

.9983 

.9985 

87 

.9986 

.9388 

.9989 

.9990 

.9992 

.9993 

88 

.9934 

.9395 

9996 

.9997 

.9997 

.9993 

89  !   .9998 

.9999  i   .9999 

.9999    1.0000    1.0000 

86 


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90  PRACTICAL    MINING 

MINING  LAWS. 

The  Legislature  of  1897  enacted  more  mining 
laws  than  any  previous  legislative  body  in  the 
State. 

Through  the  exertions  of  the  Legislative  Com- 
mittee of  the  Miner's  Association,  of  which 
Tirey  L.  Ford  is  chairman,  and  also  the  good 
work  done  by  Joseph  H.  Neff,  President; 
Samuel  Thornton,  Vice  President,  and  Julian 
Sountag,  Secretary  of  the  Association,  backed 
by  Assemblyman  Howard  of  Sierra,  who  held 
the  proud  position  of  Chairman  of  the  Assembly 
Committee  on  Mines  and  Mining,  and  who  was 
the  principal  factor  in  obtaining  favorable  mining 
legislation,  Senators  Presk  of  Nevada,  Boyce  of 
Santa  Barbara,  Chapman  of  El  Dorado,  Cleaves 
of  Shasta,  Shine  of  Tuolumne,  Smith  of  Kern 
and  Voorhies  of  Amador  counties,  and  Assem- 
blymen Caminetti  of  Amador,  Power  of  Placer, 
Robinson  of  Nevada,  Burnham  of  El  Dorado  and 
Fontana  of  Calaveras  counties,  more  legislative 
enactments  of  a  practical  character  were  pushed 
through  to  the  Governor,  who  signed  them  will- 
ingly, than  at  any  other  period  in  the  history  of 
the  State. 

Among  the  many  measures  which  were  intro- 
duced and  finally  passed  were  the  following: 


PRACTICAL   ASSAYING  91 

First;  All  legal  impediments  were  removed  from 
the  appropriation  of  $250,000,  which  was  allowed 
by  the  State  for  the  impounding  of  debris,  thus 
making  available  for  that  object  $500,000,  as  the 
General  Government  had  already  appropriated  a 
like  amount  pending  the  action  of  the  State 
Legislature. 

Second;  An  act  providing  for  the  manner  of 
locating  and  recording  mining  claims. 

And  it  is  a  remarkable  fact  that  though  Cali- 
fornia was  the  first  State  to  make  large  and  won- 
derful discoveries  of  gold,  it  was  the  last  to  enact 
laws  regulating,  locating  and  recording  of  miner- 
al claims.  Every  other  mining  State  and  Terri- 
tory passed  laws  to  cover  these  important  points 
as  soon  as  the  conditions  presented  themselves; 
but  the  Golden  State— the  State  replete  with  the 
history  of  Argonauts  and  mushroom  millionaires 
—the  mecca  of  prospectors  for  the  past  quarter 
of  a  century;  neglected  to  protect  her  miners  by 
wholesome  laws  until  this  late  day.  The  folio w- 
is  a  copy  of  Assembly  Bill,  No.  551. 

SECTION  1.  The  location  of  mining  claims 
upon  the  public  domain  of  the  United  States 
shall  be  made  and  perfected  as  provided  in  this 
Act. 

SEC.  2.  The  discoverer  of  any  vein  or  lode 
shall  immediately,  upon  making  discovery,  erect 


92  PRACTICAL    MINING 

at  the  point  of  discovery  a  substantial  monument, 
or  mound  of  rocks,  and  post  thereon  a  prelimin- 
ary notice  which  shall  contain: 

First — The  name  of  the  lode  or  claim; 

Second — The  name  of  the  locator  or  locators; 

Third — The  date  of  the  discovery ; 

Fourth — The  number  of  linear  feet  claimed  in 
length  along  the  course  of  the  vein  each  way 
from  the  point  of  discover}-; 

Fifth — The  width  claimed  on  each  side  of  the 
center  of  the  vein; 

Sixth — The  general  course  of  the  vein  or  lode, 
as  near  as  may  be; 

Seventh —  That  such  notice  is  a  first  or  pre- 
liminary notice. 

Such  notice  shall  be  recorded  in  the  office  of 
the  County  Recorder  of  the  county  in  which  the 
same  is  posted  within  twenty  days  after  the 
posting  thereof.  Upon  the  erection  of  said 
monument  and  posting  such  notice,  the  discover- 
er shall  be  allowed  the  period  of  time  specified  in 
section  three  of  this  Act  to  enable  him  to  perfect 
his  location  as  hereinafter  provided. 

SEC.  3.  Within  sixty  days  from  the  date  of 
the  discovery  of  the  vein  or  lode,  the  discoverer 
must  perform  fifty  dollars'  worth  of  labor  in  de- 
veloping his  discovery,  and  distinctly  mark  his 
location  on  the  ground  so  that  its  boundaries  can 


PRACTICAL   ASSAYING  93 

be  readily  traced,  and  must  file  in  the  office  of 
the  County  Recorder  of  the  county  in  which  the 
claim  is  situated,  a  certificate  of  location,  which 
said  certificate  shall  state: 

1.  The  name  of  the  lode  or  claim; 

2.  The  name  of  the  locator  or  locators; 

3.  The  date  of  discovery  and  posting  of  the 
notice,  provided  for  in  section  two  of  this  Act, 
which  shall  be  considered  as  the  date  of  the  lo- 
cation . 

4.  A  description  of  the  claim,  defining  the  ex- 
terior boundaries  as  they  are  marked  upon  the 
ground,  and   such  additional  description  by  re- 
ference to  some   natural   objects,  or  permanent 
monument,  as  will  identify  the  claim. 

5.  A  statement  that  such  certificate  is  the  final 
or  completed  notice  of  location,  and  that  he  has 
performed   the   aforesaid   fifty  dollars'  worth  of 
labor  in  development  work  thereon  within  the 
aforesaid  sixty  day  period,  stating  generally  the 
nature  thereof.      Said  certificate  shall  be  dated 
and  signed  by  or  on  behalf  of  the  locator  or  lo- 
cators, and  verified  by  them  or  by  some  one  in 
their  behalf,   and  when  filed  for  record  shall  be 
deemed  and  considered  as  prima  facie  evidence 
of  the  facts   therein    recited.     A   copy   of  such 
certificiate  of  location,   certified  by  the  County 
Recorder,    shall   be  admitted  in  evidence  in  all 


94  PRACTICAL    MINING 

actions  or  proceedings  with  the  same  effect  as  the 
original.  The  performance  of  snch  labor  shall  be 
deemed  a  necessary  act  in  completing  snch  loca- 
tion and  a  part  thereof,  and  no  part  thereof  shall 
inure  to  the  benefit  of  any  subsequent  location. 

SEC.  4.  The  discoverer  of  placers  or  other 
forms  of  deposit,  subject  to  location  and  appro- 
priation, under  mining  laws  applicable  to  plicers, 
shall  locate  his  claim  in  the  following  manner: 

First — He  must  immediately  post  in  a  con- 
spicuous place  at  the  point  of  discovery  thereon 
a  notice  or  certificate  of  location  thereof  contain- 
ing: 

(a)  The  name  of  the  claim. 

(b)  The  name  of  the  locator  or  locators. 

(c)  The  date  of  the  discovery  and  posting  of 
the    notice,     hereinbefore    provided   for,    which 
shall  be  considered  as  the  date  of  the  location. 

(d)  A  description  of  the  claim  by  reference  to 
legal  subdivisions  of  sections,   if  the  location  is 
made  in    conformity    with    the   public   surveys; 
otherwise,  a  description  with  reference  to  some 
natural  object  or  permanent  monument  as  will 
identify  the  claim,  and  vs  here  such  claim  is  lo- 
cated by  legal  subdivisions  of  the  public  surveys, 
such   location    shall,   notwithstanding  that  fact, 
be  marked  by  the  locator  upon  the  ground,  the 
same  as  other  locations. 


PRACTICAL   ASSAYING  95 

Second — Within  thirty  days  from  the  date  of 
such  discovery  he  must  record  such  notice  or 
certificate  of  location  in  the  office  of  the  County 
Recorder  of  the  county  in  which  such  discovery 
is  made,  and  so  distinctly  mark  his  location  on 
the  ground  that  its  boundaries  can  be  readily 
traced. 

Third — Within  sixty  days  from  the  date  of  the 
discovery  the  discoverer  shall  perform  labor  upon 
such  location  or  claim  in  developing  thereto  an 
amount  which  shall  be  equivalent  in  the  aggre- 
gate to  at  least  ten  dollars'  ($10)  worth  of  such 
labor  for  each  twenty  acres,  or  fractional  part 
thereof,  contained  in  such  location  or  claim. 

A  failure  to  perform  such  labor  within  said 
time,  shall  cause  all  rights  under  such  location 
to  be  forfeited  and  the  land  discovered  thereby 
shall  at  once  be  open  to  location  by  qualified  lo- 
cators other  than  the  proceeding  locators,  but 
shall  not  in  any  event  be  open  to  location  by 
such  proceeding  locators,  and  any  labor  per- 
formed by  them  thereon  shall  not  inure  to  the 
benefit  of  any  subsequent  locator  thereof. 

Fifth — Such  locator  shall,  upon  the  perfor- 
mance of  such  labor,  file  with  the  Recorder  of 
the  county  an  affidavit,  showing  such  perfor- 
mance, and  generally  the  nature  and  kind  of 
work  so  done. 


96  PRACTICAL   MINING 

SEC.  5.  The  affidavit  provided  for  in  the  last 
section,  and  the  aforesaid  placer  notice  or  certifi- 
cate of  location  when  filed  for  record,  shall  be 
deemed  and  considered  as  prima  facie  evidence 
of  the  facts  therein  recited.  A  copy  of  such  cer- 
tificate, notice  or  affidavit,  certified  by  the 
County  Recorder,  shall  be  admitted  in  evidence 
in  all  actions  or  proceedings  with  the  same  effect 
as  the  original. 

SEC.  6.  All  locations  of  quartz  or  placer  for- 
mations of  deposits,  hereafter  made,  which  do 
not  conform  to  the  requirements  of  this  Act,  in 
so  far  as  the  same  are  respectively  applicable 
thereto,  shall  be  void. 

SEC.  7.  No  record  of  a  mining  claim  or  mill 
site,  made  after  the  passage  of  this  Act,  in  the 
records  of  any  mining  district,  shall  be  valid. 
All  notices  of  location  of  mining  claims,  mill 
sites,  and  other  notices,  heretofore  recorded  in 
such  district  records,  if  such  notices  conform  to 
the  local  rules  and  regulations  in  force  in  such 
district,  are  hereby  declared  valid.  Within 
thirty  days  after  the  passage  of  this  Act  the 
district  recorder  or  custodian  of  the  records  of 
the  several  mining  districts  in  this  State,  shall 
transmit  to  the  County  Recorders  of  the  respec- 
tive counties,  wherein  the  respective  districts 
are  situated,  all  the  records  of  said  respective 


PRACTICAL   ASSAYING  97 

districts,  and  thenceforward  such  County  Re- 
corder shall  be  deemed  and  considered  the  legal 
custodian  of  such  records.  Thereafter  copies  of 
such  records,  certified  by  the  County  Recorder, 
may  be  received  in  evidence  with  the  same  effect 
as  the  originals. 

SEC.  8.  This  Act  shall  take  effect  and  be  in 
force  sixty  days  after  its  passage. 

Third;  The  act  of  1880,  which  provided  a 
penalty  of  $1,000  for  failure  of  any  mining  com- 
pany to  post  monthly  accounts  in  its  office,  was 
amended  so  as  to  allow  any  stockholder  to  sue 
for  any  ACTUAL  damage  sustained  by  a  neglect 
to  post  such  notice.  The  old  law  worked  a 
hardship  on  the  small  companies,  located  perhaps 
miles  from  any  town,  in  mountainous  districts, 
where  it  would  be  sometimes  difficult  to  post 
such  monthly  statements.  With  the  exception 
of  the  right  to  sue  for  actual  damages  instead  of 
the  $1,000  specified  in  the  old  statute,  the  law  is 
still  in  force. 

Fourth;  By  a  law  enacted  by  the  recent  Legis- 
lature it  requires  the  consent  of  the  majority  of  the 
stock,  instead  of  two  thirds  of  the  stock  as  hereto- 
fore, before  any  transfer  of  real  estate  can  be  made 
by  any  mining  company,  and  a  record  of  such  con- 
sent must  be  filed  in  the  County  Recorder's  office. 


98  PRACTICAL    MINING 

Fifth;  Where  titles  are  given  to  town  site  lo- 
cators through  the  Superior  Judge  of  the  district, 
preferance  will  in  all  cases  be  given  to  mining 
locators. 

All  these  are  good  measures,  and  the  Miners' 
Association  may  well  be  proud  of  its  work. 


PRACTICAL   ASSAYING  99 


GLOSSARY. 

AIR  FURNACE,  A  fireplace  at  the  surface  for  drawing 
out  foul  air  from  shafts  or  levels  by  its  natural  draught 
from  combustion. 

ALUMINA,  Oxidized  aluminum  extracted  from  clays, 
creolite,  kaolin,  bauxite,  and  what  is  generally  known 
as  chalk  rock,  or  aluminite. 

ANGLES,  DIPS  and  SPURS,  The  side  extent  which  can 
be  claimed  upon  a  mineral  vein  is  expressed  by  these 
phrases. 

ANHYDROUS,  Waterless,  as  salts  or  minerals. 

ANTIMONY,  A  mineral,  symbol  Sb.  Atomic  weight,  129. 

AQUEOUS,  A  water  solution. 

ARBORESCENT,  A  tree-like  formation  of  minerals. 

ARGOL,  Crude  tartar.  An  acid  salt  deposited  from 
wine. 

ARSENATE,  Arsenic  acid  united  with  a  base. 

ARSENIRET  or  ARSENIDE,  Arsenic  in  chemical  com- 
bination with  some  base,  as  arsenide  of  iron,  sulphur  or 
bismutfi. 

BASALT,  An  effusive  rock  composed  mostly  of  pyrox- 
ene, olivine  and  silica. 

BISMUTH,  A  metal.     Symbol  Bi.  Atomic  weight  213. 

BLACKJACK,  Sulphuret  of  zinc. 

BOYER,  The  name  of  a  common  rock  drill. 

BREAST  or  BREASTING,  The  standing  end  of  rock, 
vein  or  cliff  of  gravel  immediately  before  taking  down 
and  blasting  is  called  breasting. 


100  PRACTICAL    MINING 

BRECCIA,  Cemented  rock  composed  of  angular  frag- 
ments of  one  or  more  minerals  which  generally  exhibit 
different  colors. 

CALCINE,  To  burn  off  and  volatize. 

CALCIUM,  The  metalic  base  of  lime. 

CALC  SPAR,  A  pure  crystalized  or  borate  of  soda  and 
carbonate  of  lime,  sometimes  combined  with  the  matrix 
in  vein  matter. 

CAP  ROCK,  The  uncertain  upper  rock  which  covers 
the  older  bedrock . 

CARBONATE,  Carbonic  acid  combined  with  a  base  as 
carbonate  of  lead. 

CARBONATE  OF  SODA,  Carbonic  acid  and  oxide  of  so- 
dium chemically  combined. 

CARBONIFEROUS,  As  carboniferous  slate  or  shale, 
containing  a  little  carbon,  indicative  of  underlying  coal 
seams. 

COUNTER  LODE,  A  vein  obliquely  crossing  the  reg- 
ular veins  of  the  district. 

CELLULAR,  When  a  stone  or  mineral  has  many  small 
cavities,  sponge- like. 

CHLORIDE,  Chlorine  chemically  united  with  some 
base,  as  chloride  of  sodium  (common  salt),  especially 
found  in  manganese  which  when  dissolved  in  muriatic 
acid  gives  off  the  fumes  of  chlorine  gas. 

CLAY,  Chiefly  composed  of  alumina  in  a  moist  and 
putty-like  or  dry,  pulverized  condition,  often  found  be- 
tween the  vein  matter  and  the  footwall  rock  as  gouge. 

CLAY  COURSE,  Mostly  applied  to  a  common  clay  seam 
or  gouge  on  the  side  of  a  vein. 


PRACTICAL   ASSAYING  101 

CLEAVAGE,  The  planes  at  which  cleavable  stones 
break. 

COBALT,  A  magnetic  metal,  Atomic  weight,  29.5. 

COHERENT,   Firmly  held  together,  not  friable. 

COMPACT,  When  a  stone  is  all  alike,  not  cleavable. 

CONCHOIDAL,  Fracturing  to  an  irregular  shaped  sur- 
face like  flint;  brick  or  sand  rock  without  any  sign  of 
plane  or  cleavage. 

CONGLOMORATE,  A  pudding  stone  or  cementation  of 
rocks,  pebbles  and  sand. 

CUPEL,  A  moulded  cup  of  bone  ash  for  cupelling  lead 
from  the  assay,  leaving  the  gold  and  silver  in  the  form 
of  a  bead. 

CUPRIFEROUS,  Containing  copper,  as  copper  ores. 

DECOMPOSED,  That  which  has  undergone  artificial  or 
natural  change,  as  the  desulphurization  and  oxidation 
of  the  sulphurets  and  other  metals. 

DENDRITIC  or  ARBORESCENT,  Shaped  or  crystalized 
like  trees. 

DETRITUS,  Finely  powdered  deposits  worn  from  hard 
substances. 

DIKE,  A  large  zone  or  vein-like  formation  but  com- 
posed of  bed  rock  or  country  rock  instead  of  quartz. 

FAULT,  A  cut-off  or  shift  of  a  vein  or  seam. 

FERRUGINOUS,  Iron,  iron  oxide,  containing  iron. 

FISSURE,  An  extensive  crack  or  chasm  in  a  somewhat 
regular  plane  of  fracture,  as  a  true  fissure  vein. 

FLOAT  STONES,  Sometimes  called  shoal  rock,  miner- 
alized rock  lying  upon  the  surface  or  near  vein  deposits. 
It  sometimes  directs  the  prospector  to  the  vein  or  lode 
from  which  it  came. 


102  PRACTICAL    MINING 

FLUX,  Any  substance  that  is  favorable  to  combustion, 
oxidixatiou  or  reduction  by  fire. 

FOLIATED,  Lamillar  or  leaf-like  in  form,  which  can 
be  cleaved. 

Fox  WEDGE,  Wedged  at  two  points.  We  find  gash 
veins  fox  wedged. 

FRACTURE,  Applied  to  qualify  the  broken  surfaces  of 
minerals,  as  even  or  uneven  fracture. 

FRANGIBLE,  Not  tough,  easily  broken,  brittle. 

GANGUE,  Waste,  all  kinds  of  enclosing  waste  rock, 
the  matrix  of  quartz,  etc.,  but  gangues  may  not  all  be 
matrixes. 

GLANCE,  Sometimes  applied  to  glancing  or  shining 
mineral,  as  copper  glance,  lead  glance,  silver  glance. 

GLOBULAR  CONCRETIONS,  Minerals  occurring  in 
small,  rounded  forms. 

GOSSAN,  Very  rusty  and  finely  powdered  quartz.  It  is 
thought  to  be  one  of  the  best  indications  for  minerals  in 
deep  sections  of  the  vein. 

GOUGE,  Soft  clay  seam  between  the  vein  matter  and 
the  walls. 

GRAMME,  Equal  to  15,433  grains  Troy. 

GRANULAR,  Minerals  exhibiting  small  grains  across 
the  plane  of  the  fracture. 

GRAPHITE,  A  mineral  carbon. 

GREENSTONE,  A  green  colored,  granular  stone,  a  kind 
of  trap,  composed  of  hornblende  and  feldspar. 

HORN  SILVER,  The  common  name  for  chloride  silver 
because  it  has  a  horn-like  surface. 

HORSE,  A  long,  convex-sided  portion  of  a  foreign  rock 
completely  inclosed  in  the  quartz  or  vein  matter. 


PRACTICAL   ASSAYING  103 

HYDRAULIC  CEMENT,  A  mixture  of  lime,  magnesia, 
alum  and  silica  so  that  it  solidifies  under  water. 

INCRUSTED,  When  a  surface  is  covered  with  some 
other  deposit. 

INTERLACING,  When  the  threads  or  ribbons  of  one 
mineral  cross  those  of  another. 

INTERSTRATIFIED,  Lying  between  other  stratifica- 
tions, as  a  layer  of  greenstone  between  other  layers  of 
slate. 

LAVA,  Igneous  rock  that  has  been  melted,  forced  up 
or  thrown  out  from  volcanoes. 

MATTE,  The  product  of  the  first  incomplete  reduction 
of  an  ore,  as  copper  matte. 

MICA,  A  thin,  scale-like  mineral  of  the  true  granite. 

OXIDE,  A  chemical  combination  of  oxygen  with  a 
base. 

OXYGEN,  A  gas  we  extract  from  the  air  in  breathing; 
it  also  forms  with  many  acids;  one-half  the  weight  of 
solid  1  edrock.  When  united  with  hydrogen  it  is  water. 

PALEOZOIC,  Applied  to  the  first  rocks  with  fossil  ani- 
mals and  to  the  older  divisions  of  geologic  time.  It  in- 
cludes the  silurian,  devonian  and  car  oniferous  ages. 

PLATINUM,  A  grayish-white  metal  infusible  by  ordi- 
nary means,  insoluble  in  any  single  acid.  It  dissolves  in 
a  mixture  of  nitric  acid  one  part,  hydrochloric  acid  three 
parts. 

SCHIST  or  SCHISTOSE,  A  crystaline  or  metamorphic 
rock  having  a  slaty  structure,  as  mica  schist,  argilla- 
ceous schist,  etc. 

SECTILE,  Minerals  which  are  sufficiently  tough  to  cut 
smootHly  without  crumbling. 

SERPENTINE,  Composed  of  the  mineral  serpentine, 
feldspar,  and  pyroxene. 


14  DAY  USE 

RETURN  TO  DESK  FROM  WHICH  BORROWED 

LOAN  DEPT. 

This  book  is  due  on  the  last  date  stamped  below,  or 

on  the  date  to  which  renewed. 
Renewed  books  are  subject  to  immediate  recall. 


LD 


LD  21A-60m-3,'65 
(F2336slO)476B 


General  Library 

University  of  California 

Berkeley 


